| Official Name: | Dan Sai |
| Native Name: | ด่านซ้าย |
| Native Name Lang: | th |
| Settlement Type: | District |
| Subdivision Type: | Country |
| Subdivision Name: | Thailand |
| Subdivision Type1: | Province |
| Subdivision Name1: | Loei |
| Subdivision Type2: | Seat |
| Subdivision Name2: | Dan Sai |
| Subdivision Type3: | Subdistricts |
| Subdivision Name3: | 10 |
| Subdivision Type4: | Mubans |
| Subdivision Name4: | 99 |
| Established Title: | Districtestablished |
| Population Total: | 51564 |
| Population As Of: | 2015 |
| Blank Name Sec1: | Postal code |
| Blank Info Sec1: | 42120 |
| Blank Name Sec2: | Geocode |
| Blank Info Sec2: | 4205 |
| Timezone: | ICT |
| Utc Offset: | +7 |
| Coordinates: | 17.28°N 101.1467°W |
Dan Sai (Thai: ด่านซ้าย; in Thai pronounced as /dàːn sáːj/) is a district (amphoe) in the western part of Loei province, northeastern Thailand.
Neighboring districts are (from the east clockwise): Phu Ruea of Loei Province; Lom Kao and Khao Kho of Phetchabun province; Nakhon Thai of Phitsanulok province; and Na Haeo of Loei. To the north is Xaignabouli province of Laos.
The source of the Pa Sak River is in the mountains in the eastern part of the district. A large part of the district is a portion of the Phu Hin Rong Kla National Park. Phu Thap Buek, the highest mountain of the Phetchabun Range, is at the southern end of the district.[1] To the southeast is the Phu Luang Wildlife Sanctuary.
The northern part of the district reaches the southern end of the Luang Prabang Range mountain area of the Thai highlands.[2]
According to General Apirat Kongsompong, on 5 November 1976, King Rama X, then an army captain and crown prince, engaged with communist insurgents in Ban Mak Kheng of Dan Sai District. The general noted that, "His Majesty was in the operation base, ate and slept like other soldiers. His Majesty visited local residents, gave moral support and fought shoulder by shoulder with brave soldiers."[3]
Dan Sai is divided into 10 sub-districts (tambons), which are further subdivided into 99 administrative villages (mubans).
| No. | Name | Thai | Villages | Pop.[4] | |
|---|---|---|---|---|---|
| 1. | Dan Sai | Thai: ด่านซ้าย | 15 | 9,490 | |
| 2. | Pak Man | Thai: ปากหมัน | 7 | 3,034 | |
| 3. | Na Di | Thai: นาดี | 9 | 3,810 | |
| 4. | Khok Ngam | Thai: โคกงาม | 7 | 4,854 | |
| 5. | Phon Sung | Thai: โพนสูง | 9 | 5,026 | |
| 6. | Ipum | Thai: อิปุ่ม | 13 | 4,723 | |
| 7. | Kok Sathon | Thai: กกสะทอน | 12 | 7,854 | |
| 8. | Pong | Thai: โป่ง | 11 | 6,092 | |
| 9. | Wang Yao | Thai: วังยาว | 7 | 3,686 | |
| 10. | Na Ho | Thai: นาหอ | 9 | 2,995 |
There are two sub-district municipalities (thesaban tambons) in the district:
There are nine sub-district administrative organizations (SAO) in the district:
Dan Sai is the place where Phi Ta Khon traditions are known around the world. The Thai spirit masked festival is held annually after the full moon of the sixth Thai lunar month (around late June to early July).[5]