Recursive islands and lakes explained

A recursive island or lake, also known as a nested island or lake, is an island or a lake that lies within a lake or an island.^[1] For the purposes of defining recursion, small continental land masses such as Madagascar and New Zealand count as islands, while large continental land masses do not. Islands found within lakes in these countries are often recursive islands because the lake itself is located on an island.

Recursive islands

Islands in lakes

See main article: Lake island. Only a few notable examples are given.

width=130px	Island	width=130px	In lake	width=90px	Country	Area (km^2)	width=180px	Coordinates	Notes
Manitoulin Island	Lake Michigan–Huron	Canada	2,766	45.6522°N -82.1089°W	Largest lake island in the world^[2]
René-Levasseur Island	Manicouagan Reservoir	Canada	2,020	51.3972°N -68.6917°W	The island is artificial as the lake it is in was made by flooding a smaller existing lake due to the creation of the Daniel-Johnson dam.
Soisalo	spread across several lakes	Finland	1,638	62.4828°N 28.1314°W	The largest island in continental Finland. It has shores to four different lakes (Kallavesi, Unnukka, Suvasvesi and Kermajärvi), but they are not all at the same level.
Sääminginsalo	Saimaa	Finland	1,090	61.9828°N 29.0814°W	Separated from one side by an artificial canal (Raikuu canal).
Olkhon Island	Lake Baikal	Russia	730	53.1567°N 107.3836°W
Isle Royale	Lake Superior	United States	535	48°N -88.9167°W
Ukerewe Island	Lake Victoria	Tanzania	530	-2.0294°N 33.01°W
St. Joseph Island	Lake Michigan–Huron	Canada	365	46.2197°N -83.9464°W
Drummond Island	Lake Michigan–Huron	United States	347	46°N -83.6667°W
Idjwi	Lake Kivu	DR Congo	340	-2.1661°N 29.0558°W
Kotasaari	Kallavesi	Finland	285	62.8811°N 28.0064°W	Separated from one side by an artificial canal (Summa canal).
Ometepe	Lake Nicaragua	Nicaragua	276	11.5°N -85.5833°W	Made of two conjoined volcanic islands
Zapatera	Lake Nicaragua	Nicaragua	54	11.73°N -85.82°W
Big island	Lake of the Woods	Canada	~200	61.1292°N -116.7567°W
Mercer Island	Lake Washington	United States	33.4^[3]	47.5775°N -122.212°W	Crossed by the Lacey V. Murrow Memorial Bridge, the second longest floating bridge in the world.
Duck Island	Green Lake	United States		47.6794°N -122.3414°W
Wizard Island	Crater Lake	United States	1.3	42.9386°N -122.1456°W	Crater Lake itself is a caldera formed by the eruption of Mount Mazama; a series of smaller eruptions later formed cinder cones on the caldera floor, of which Wizard Island is the highest, and the only one now visible above the lake's surface.^[4]
—	Orba Co	China		34.5456°N 81.0392°W	Highest-elevation islands in the world. There are three islands of quite similar size.
Silcox Island	American Lake	United States		47°07′44″N 122°33′53″W	There are residents that live on this island, there is no ferry service to them.

Islands in lakes on islands

There are nearly 1,000 islands in lakes on islands in Finland alone.^[5]

Name	In lake	On island	Country	Area (km^2)	Coordinates	Notes
Samosir	Lake Toba	Sumatra	Indonesia	630	2.5833°N 98.8167°W	Largest island in a lake on an island. Manmade from digging canal
Gatter Island	Lake Hazen	Ellesmere Island	Canada	0.2	81.9181°N -69.0931°W
Glover Island	Grand Lake	Newfoundland	Canada	178	48.7811°N -57.6983°W	Largest naturally occurring island in a lake on an island.
Motutaiko Island	Lake Taupō	North Island	New Zealand	0.11	-38.8547°N 175.9433°W
Goodin Island	Lake Campbell	Fidalgo Island	United States	0.09	48.4384258, -122.6168703
Mokoia Island	Lake Rotorua	North Island	New Zealand	1.35	-38.0806°N 176.2847°W
Rahui Island	Lake Waikareiti	North Island	New Zealand		-38.7125°N 177.175°W	Largest of several islets in Lake Waikareiti
Mou Waho	Lake Wanaka	South Island	New Zealand	1.2	-44.5528°N 169.0806°W	Largest of several islets in Lake Wanaka, including Stevensons Island
Pigeon Island	Lake Wakatipu	South Island	New Zealand	1.7	-44.925°N 168.3972°W	Largest of several islets in Lake Wakatipu, including Pig Island / Mātau and Hidden Island
Pomona Island	Lake Manapouri	South Island	New Zealand	2.6	-45.5083°N 167.475°W	Largest of several islets in Lake Manapouri; largest lake island in New Zealand
Motmot Island	Lake Wisdom	Long Island	Papua New Guinea	0.04	-5.3522°N 147.1172°W
—	West Lake	Brownsea Island	United Kingdom	0.0008	50.6928°N -1.9725°W
Belle Isle	Windermere	Great Britain	United Kingdom	0.17	54.3619°N -2.9344°W
Storgrynnan	Vandöfjärden	Fasta Åland	Finland	0.12	60.2961°N 19.92°W
—	Senanayaka Samudra	Sri Lanka	Sri Lanka	0.02	7.2°N 81.5194°W
Derrywarragh Island	Lough Neagh	Ireland	United Kingdom	0.56	54.5158°N -6.5697°W
Boa Island	Lower Lough Erne	Ireland	United Kingdom	5.3	54.5241°N -7.7992°W^[6]
Sveta Marija	Veliko jezero	Mljet	Croatia	0.017	42.7689°N 17.3603°W
Chikubu Island	Lake Biwa	Honshu	Japan	0.14	35.4222°N 136.1436°W
Takeshima	Lake Biwa	Honshu	Japan	0.6	35.2964°N 136.1781°W
Okishima	Lake Biwa	Honshu	Japan	1.51	35.2078°N 136.0661°W	Largest of the three islands located within Lake Biwa, which is Japan's largest lake.
Nakajima (Lake Kussharo)	Lake Kussharo	Hokkaido	Japan	5.81	43.6322°N 144.3056°W	Largest recursive island in Japan
Nakajima (Lake Toya)	Lake Tōya	Hokkaido	Japan	4.84	42.6019°N 140.8531°W
Takeshima	Lake Biwa	Honshu	Japan	0.6	35.2964°N 136.1781°W
Okinajima	Lake Inawashiro	Honshu	Japan	0.07	37.5092°N 140.0375°W
Loeha Island	Lake Towuti	Sulawesi	Indonesia	12.5	-2.7728°N 121.5475°W
Lalu Island	Sun Moon Lake	Nantou	Taiwan	0.882	23.8556°N 120.9111°W
Yufei Island	Qingcao Lake	Hsinchu	Taiwan	0.00425	24.7747°N 120.9717°W
—	Kasegalik Lake	Flaherty Island	Canada			There are several other islands in that lake.
Isla Cabritos	Lago enriquillo	Hispaniola	Dominican Republic	16.67	18°29'22''N 71°40'56''W||-|—|—|Cat Ba Island|Vietnam|0.0005|20°46'54"N 107°05'30"E|There is a smaller one, right at the south of it.|-|—|Blöndulón|Iceland|Iceland|||There are nine other islands in this lake, all significantly smaller than this one.|} Islands in lakes on islands in lakes Name In lake On island In lake width=90px Country ! Area (km^2) width=180px Coordinates ! Notes Kokkosaari Kokkohauta Sääminginsalo Saimaa Finland 0.88 61.9889°N 29.2153°W Claimed to be the world's largest island in a lake in an island in a lake. Another island, Suursaari (62.0911°N 28.9911°W) in Hanhijärvi, is also located in Sääminginsalo, and is about half the size of Kokkosaari. Separated by an artificial canal, Sääminginsalo might not be considered an island. — Lake Chaunoy (Lac du Chaunoy)^[7] René-Levasseur Island Manicouagan Reservoir Canada 0.44 51.5514°N -68.8189°W René-Levasseur Island is an artificial island, formed when the Manicouagan reservoir was flooded in 1970. There are also more than 10 other smaller islands in Lake Chaunoy, the largest of which is less than a tenth of the size of the one listed here. Treasure Island Lake Mindemoya Manitoulin Island Lake Michigan–Huron Canada 0.4 45.7639°N -82.1781°W Largest natural island on a lake on an island on a lake. Lake Kagawong Manitoulin Island Lake Michigan–Huron Canada 0.24 45.8125°N -82.3061°W Ryan Island^[8] Siskiwit Lake Isle Royale Lake Superior United States 0.141 48.01°N -88.7708°W Largest island in the largest lake on the largest island in the largest lake in the world (Lake Superior) — Second Lake Drummond Island Lake Michigan–Huron United States 0.044 46.0506°N -83.5986°W —^[9] Mackaysee Lake Chambers Island Green Bay, Lake Michigan United States 0.009 45.1947°N -87.3453°W — Frith Lake Kelvin Island Lake Nipigon Canada 0.0013 49.8747°N -88.6814°W Piiroonsaari Saravesi Kotasaari Kallavesi Finland 0.22 62.8447°N 28.0767°W Separated by an artificial canal, Kotasaari might not be considered an island. Suurisaari Oininki Äitsaari Saimaa Finland 0.14 61.3158°N 28.6336°W Ukonsaari Kulkemus Partalansaari Pihlajavesi (Saimaa) Finland .12 61.6692°N 28.3953°W — Lake Cancy René-Levasseur Island Manicouagan Reservoir Canada 0.011 51.5558°N -68.8478°W — Lac des Pigamons Îlots Walcott Lake Mistassini Canada 0.0002 51.1217°N -73.3594°W — — Wilson Island Great Slave Lake Canada 0.011 61.8353°N -112.7825°W Raaskasaari Kylliönjärvi Viljakansaari Pihlajavesi (Saimaa) Finland 0.05 61.5647°N 28.3822°W — — Kållandsö Vänern Sweden 0.0027 58.6978°N 13.1883°W There is a second island in the lake, almost the exact same size Ösjöholmen Ösjön Ammerön Revsundssjön Sweden 0.008 62.8658°N 15.1731°W — — Tynnelsö Mälaren Sweden 0.0005 59.4169°N 17.0789°W — — — Lake Kovdozero Russia 0.0162 66.7564°N 31.9769°W — — Shaganappie Island Wollaston Lake Canada 0.0066 58.3728°N -102.9642°W — Calder Lake Malcolm Island Reindeer Lake Canada 0.0154 56.9733°N -102.1336°W — — Ispatinow Island Cree Lake Canada 0.00019 57.4611°N -106.6797°W — — Blanchet Island Great Slave Lake Canada 0.01 61.9944°N -112.5156°W Several small islands in this lake — Vanooyen Lake Shakespeare Island Lake Nipigon Canada 0.0182 49.66°N -88.4028°W There is a second, smaller island in this lake. — Margaret Lake Elk Island God's Lake Canada 0.00095 54.6589°N -94.1789°W Several small islands in this lake — — Ile Guillaume Couture Lac Mistassini Canada 0.0017 50.9169°N -73.6256°W — — Ile Tchapahipane Lac Mistassini Canada 0.00125 51.0761°N -73.4236°W — — Pie Island Lac Mistassini Canada 0.0086 48.2328°N -89.0572°W Two islands of similar size are in this lake — Muir Lake St Ignace Island Lake Superior Canada 0.00325 48.8078°N -88.0342°W — Antler Lake St Ignace Island Lake Superior Canada 0.0041 48.8164°N -88.0014°W Two islands of similar size are in this lake — Williamson Lake St Ignace Island Lake Superior Canada 0.00425 48.8011°N -88.0275°W — Molinski Lake Simpson Island Lake Superior Canada 0.01 48.8203°N -87.7142°W — Caribou Lake Simpson Island Lake Superior Canada 0.00465 48.7642°N -87.6592°W — Veronica Lake Slate Islands Lake Superior Canada 0.0065 48.6578°N -86.9897°W — Michi Lake Michipicoten Island Lake Superior Canada 0.0037 47.7411°N -85.9081°W There are three islands in total in this lake — Channel Lake Michipicoten Island Lake Superior Canada 0.0084 47.7306°N -85.8°W A second, smaller island is immediately to the west of this one. — — — Knielinger See Germany 0.0003 49.0313°N 8.3095°W — — Wizard Island Crater Lake United States — Lac Civic Île Bronson Réservoir Cabonga Canada There are other islands in lakes on islands in Cabonga. Islands in lakes on islands in lakes on islands Name In lake On island In lake On island Country Area (m^2) Coordinates Notes — — — Nettilling Lake Baffin Island Canada 40,000 66.6875°N -70.48°W There are more islands in lakes on the 'level 2' island in Nettling Lake. — — — — Victoria Island Canada 16,000 69.7922°N -108.2406°W Sometimes unofficially referred to as Inception Island. — Aek Natonang (Locally Sidihoni Lake^[10]) Samosir Lake Toba Sumatra Indonesia 13,125 2.5644°N 98.8833°W Two islands, the largest of which is 175 m by 75 m. — — Glover Island Grand Lake Newfoundland Canada 7,500 48.7967°N -57.6578°W There are several (at least seven) other, even smaller, islets in the lake — — Glover Island Grand Lake Newfoundland Canada 2,300 48.7189°N -57.7731°W In a lake 11 km south west to the lake that contains the larger island. There are no other island in this island's lake — — — Meelpaeg Reservoir Newfoundland Canada 100 48.3122°N -56.5133°W There are 3 other smaller islands in the same lake. — Arethusa Pool Mou Waho Lake Wānaka South Island New Zealand 225 -44.5542°N 169.0842°W There are two islands in this lake, both less than 25 m across. — — Eilean Sùbhainn Loch Maree Great Britain United Kingdom 225 57.69°N -5.4858°W Two islets, each of which is 15m by 15m — — — Kooryet Lake Banks Island (British Columbia) Canada ~100 53.3519°N -129.9917°W A number of small islets, the largest of which is only 10m across — — Samosir Lake Toba Sumatra Indonesia 400 2.6364°N 98.8372°W — — — Jubilee Lake Newfoundland Canada 20 48.0639°N -55.1733°W Several small islets, the largest of which is about 5 m across — — Cayo pajaro Laguna de Leche Cuba Cuba 832 22.2253°N -78.6672°W There are several other islets in the lake, all about half the area of the specified islet. — — — Lago Windhond Isla Navarino Chile 30 -55.1115°N -67.5926°W Approximately 50 other smaller and similar sized islets are present in the immediate surrounding area. Vulcan Point^[11] ^[12] Main Crater Lake Volcano Island^[13] Lake Taal Luzon Philippines 14.0097°N 120.9983°W Islands in lakes on islands in lakes on islands in lakes !Name!In lake!On island!In lake!On island!In lake!Country!Size(km^2)!Coordinates!Notes — — — — — Yathkyed Canada 62.6511°N -97.7872°W ^[14] ^[15] Moose Boulder was claimed to exist in the seasonal pond of Moose Flats on Ryan Island in Siskiwit Lake on Isle Royale in Lake Superior in the United States.^[16] In 2020, an expedition to the island found that it is potentially a hoax, along with the aforementioned seasonal pond.^[17] Recursive lakes Lakes on islands Only a few notable examples are listed. Name On island Country Size (km^2) Coordinates Notes Nettilling Lake Baffin Island Canada 5,542 66°29′N 70°20′W Lake Alaotra Madagascar Madagascar 900 17.5°S 48.5°E Laguna de Leche Cuba Cuba 67.2 22.2092°N -78.6214°W Lough Neagh Island of Ireland Northern Ireland/United Kingdom 392 54.6183°N -6.3953°W Lough Corrib Island of Ireland Republic of Ireland 176 53°26′N 9°14′W Loch Lomond Great Britain Scotland/United Kingdom 71 56°05′N 4°34′W Lake Kawaguchi Honshu Japan 6.13 35.5156°N 138.76°W The largest among the Fuji Five Lakes Þingvallavatn Iceland Iceland 84 64°11′N 21°09′W Lake Taupō North Island New Zealand 616 -38.8069°N 175.9078°W Lake Wakatipu South Island New Zealand 289 -45.05°N 198°W Lake Biwa Honshu Japan 670 35°20′N 136°10′E Largest lake in Japan Lake Toba Sumatra Indonesia 1130 2.68°N -98.88°W Lake Ranau Sumatra Indonesia 126 -4.8625°N 103.9306°W Lake Singkarak Sumatra Indonesia 108 -0.62°N 100.54°W Lake Towuti Sulawesi Indonesia 561 -2.75°N 121.5°W Lake Poso Sulawesi Indonesia 323 -1.9244°N 120.6167°W Lake Matano Sulawesi Indonesia 164 -2.4853°N 121.3333°W Lakes on islands in lakes Name On island In lake Country Size (km^2) Coordinates Notes Lake Manitou Manitoulin Island Lake Michigan–Huron Canada 106 45.7783°N -81.9917°W Ylä-Enonvesi^[18] Sääminginsalo Saimaa Finland 12 62.0519°N 29.0033°W Includes Lake Saarijärvi that forms its southern part. Separated by an artificial canal, Sääminginsalo might not be considered an island. Kulkemus Partalansaari Pihlajavesi (Saimaa) Finland 5.8 61.6786°N 28.4036°W Saajuu-Palovesi Partalansaari Pihlajavesi (Saimaa) Finland 4.1 61.6986°N 28.3261°W Saravesi Kotasaari Kallavesi Finland 4.1 62.8469°N 28.0811°W Separated by an artificial canal, Kotasaari might not be considered an island. Oininki Äitsaari Saimaa Finland 2.6 61.3144°N 28.6392°W Malosenjärvi Viljakansaari Pihlajavesi (Saimaa) Finland 1.4 61.5328°N 28.2697°W Valkiajärvi Hurissalo Saimaa Finland 1.4 61.5075°N 27.8247°W Ruokojärvi Partalansaari Pihlajavesi (Saimaa) Finland 1.3 61.6336°N 28.3942°W Närtejärvi Viljakansaari Pihlajavesi (Saimaa) Finland 1.2 61.5753°N 28.5189°W Kylliönjärvi Viljakansaari Pihlajavesi (Saimaa) Finland 1.1 61.5631°N 28.3831°W Lapinjärvi Hurissalo Saimaa Finland 1.1 61.4925°N 27.8083°W Shara-Nur^[19] Olkhon Island Lake Baikal Russia 53.105°N 107.2544°W Siskiwit Lake Isle Royale Lake Superior United States 16.8 48.0014°N -88.7972°W Lake Desor^[20] Isle Royale Lake Superior United States 47.9767°N -88.9869°W Lake Richie^[21] Isle Royale Lake Superior United States 48.0439°N -88.6953°W Lake Mindemoya Manitoulin Island Lake Michigan–Huron Canada 38.7 45.7619°N -82.2089°W Lake Kagawong Manitoulin Island Lake Michigan–Huron Canada 55.6 45.8333°N -82.31°W Little Lake Washington Island Lake Michigan United States 0.17 45.41°N -86.9414°W Lake Windigo Star Island Cass Lake (Minnesota) United States 0.8 47.4186°N -94.5703°W Fox Lagoon Pelee island Lake Erie Canada 0.02 41.7325°N -82.6717°W Lake Henry Pelee island Lake Erie Canada 0.345 41.8256°N -82.6389°W Laguna del Volcan Maderas^[22] Ometepe Lake Nicaragua Nicaragua 0.034 11.445°N -85.5106°W Laguna de Zapatera^[23] Zapatera Lake Nicaragua Nicaragua 0.19 11.7664°N -85.8569°W Antoniyevskoye Lake Valaam Lake Ladoga Russia 0.028 61.3883°N 30.9967°W Ozero Leshchevo Valaam Lake Ladoga Russia 0.27 61.3597°N 30.9328°W Lake Geneserath Beaver Island Lake Michigan–Huron United States 2 45.5986°N -85.5397°W Ösjön Ammerön Revsundssjön Sweden 0.58 62.8647°N 15.1725°W Igelviken Färingsö Mälaren Sweden 0.47 59.3647°N 17.7036°W Ändsjön Frösön Storsjön Sweden 0.32 63.1761°N 14.5733°W Gråtjønna Røssvassholmen Røssvatnet Norway 0.05 65.6961°N 13.9964°W — — Lake Chad Cameroon There is another, smaller lake on that island.There are a few more islands in Lake Chad that have a lake on them. Süvähaud Piirissaar Peipus Estonia — — Thac Ba Reservoir Vietnam 0.05 21°50'24.7"N 104°58'02.5"E There are some extremely tiny islets in that lake. Lakes on islands in lakes on islands Name On island In lake On island Country Size (km^2) Coordinates Notes — — Nettilling Lake Baffin Island Canada 1.55 66.3875°N -69.6447°W — Glover Island Grand Lake Newfoundland Canada 1.40 48.8025°N -57.6614°W Arethusa Pool Mou Waho Lake Wānaka South Island New Zealand 0.05 -44.5542°N 169.0833°W — Rahui Island Lake Waikareiti North Island New Zealand 0.003 -38.7125°N 177.1728°W — — Jubilee Lake Newfoundland Canada 0.025 48.0639°N -55.1733°W — — Mölnorträsk Fårö Sweden 0.00006 57.9292°N 19.1414°W Extremely small — — — Baffin Island Canada 70.6872°N -80.5717°W Molemole Motu'a'ali Motu Si'i Niuafo'ou Tonga 0.02 -15.5949°N -175.6492°W — Sandey Þingvallavatn Iceland Iceland — Gatter Lake Lake Hazen Ellesmere Island Canada Northernmost lake of its kind in the world. — Teinholmen Vestrevatnet Osterøy Norway 60.5366°N 5.6272°W Lakes on islands in lakes on islands in lakes Only one such lake is known. See also List of endorheic basins Volcanic crater lake List of islands by area List of lakes by area List of islands by population References ]

Notes and References

1. Book: 2019 Guinness World Records. 978-1-912286-43-0. 40–41. Guinness World Records. Records. Guinness World. August 28, 2018.
2. Web site: World's Largest Island-in-a-lake-on-an-island-in-a-lake-on-an-island Seen on Google Earth. January 2012. Natalie Wolchover 24. livescience.com. January 24, 2012.
3. Web site: 2019 U.S. Gazetteer Files. United States Census Bureau. August 7, 2020.
4. Web site: Crater Lake, Oregon . NASA Earth Observatory . September 18, 2006 .
5. Web site: Suomen saaristo- ja vesistömatkailusta. valtioneuvosto.fi / Julkaisut.
6. https://www.logainm.ie/en/130609 Boa Island
7. Web site: Lac Du Chaunoy, Quebec Map. geodata.us .
8. Web site: GNIS Detail - Ryan Island. geonames.usgs.gov.
9. Web site: Islands within Chambers Island's Lake Mackaysee Now Protected by Door County Land Trust. November 8, 2018.
10. Web site: Aek Natonang Lake – A Sub-Lake of Pangururan. 2020-08-12. www.toba.indonesia-tourism.com.
11. News: Freedman. Andrew. Taal volcano's crater lake is nearly empty. January 17, 2020. Washington Post. Meko. Tim. Karklis. Laris.
12. Web site: Some interesting islands and lakes. Topografisch Verbond Elbruz. live. https://web.archive.org/web/20130919194149/http://elbruz.org/Special%20Projects/Islands%20and%20Lakes.htm. September 19, 2013. February 1, 2014.
13. Web site: Volcano Island | volcano, Philippines. Encyclopedia Britannica.
14. https://earthexplorer.usgs.gov/
15. https://curiocity.com/canada-most-recursive-island-yathkyed-lake
16. Web site: Largest island on the largest lake in the world. July 21, 2009. Albert Lea Tribune. March 13, 2020. 2009.
17. Web site: The Intrepid Mother and Son Who Unraveled a Geographic Hoax. Taub. Matthew. March 10, 2020. Atlas Obscura. en.
18. https://www.syke.fi/en-US/Open_information/Spatial_datasets/Downloadable_spatial_dataset Shoreline - lakes (Ranta10)
19. Web site: Shara-Nur lake . BaikalNature Tour Operator . May 11, 1975 . March 13, 2020.
20. Web site: GNIS Detail - Lake Desor. geonames.usgs.gov.
21. Web site: GNIS Detail - Lake Richie. geonames.usgs.gov.
22. News: Puerta laguna misteriosa [Door to mysterious lagoon]]. Orlando. Valenzuela. El Nuevo Diario. es.
23. Web site: Global Volcanism Program | Zapatera. Smithsonian Institution | Global Volcanism Program.
24. https://curiocity.com/canada-most-recursive-island-yathkyed-lake