| Keri | |
| Location: | Gulf of Finland, Baltic Sea |
| Coordinates: | 59.7°N 27°W |
| Area Ha: | 3.1 |
| Country: | Estonia |
| Country Admin Divisions Title: | maakond (county) |
| Country Admin Divisions: | Harju maakond |
| Country Admin Divisions 1: | Viimsi vald |
| Country Admin Divisions Title 2: | village |
| Country Admin Divisions 2: | Kelnase village |
| Population: | 0 |
Keri (sv|Kockskär) is a 3.1ha Estonian island in the Gulf of Finland of the Baltic Sea. It is located about 6 km north of the island Prangli, and is one of the northernmost islands of Estonia. Keri is administratively part of Kelnase village in the Viimsi municipality of the Harju county.
The uninhabited island is the site of notable Keri lighthouse.
Keri was first attested in written records in 1623. The island has long been situated by important sea routes. In 1719, a lighthouse was erected there on the order of Tsar Peter I of Russia. The present lighthouse was built in 1803.[1]
During a well drilling in 1902, natural gas was discovered. From 1906 to 1912 the gas was used to power the lighthouse and heat the other buildings on the island. During that time it was the only lighthouse in the world to be powered by natural gas. In 1912, after a seismic impulse the gas flow stopped.[2] The island has been inhabited only by the families of the lighthouse keepers. The last keeper left the island in September 2002. Since then the lighthouse operates automatically; the power is derived from a wind turbine and solar panels.
On 14 June 1940, a Finnish civilian airliner Kaleva was shot down by Soviet military aircraft and drowned near the island, killing all nine people on board. On 14 June 1993, a monument to commemorate the victims was erected on Keri. The wreck of Kaleva was found on 5 June 2024 by unmanned underwater vehicles near the Keri lighthouse in Estonian territorial waters at a depth of 71 to 76 meters.[3]