Tien Cave - Ham Yen (Tuyen Quang) Tien Cave is located in Chan Quy mountain, sandwiched between Da Den mountain and Bach Ma mountain, in Thong Nhat village (Yen Phu commune, Ham Yen district - Tuyen Quang). This complex includes 7 different caves, including: Tien Cave, Dan Da Cave, Thien Dinh Cave, Thien Cung Cave, Thach Sanh Cave, Tam Cung Cave, Am Phu Cave. All of these caves are arranged in an arc forming a unique complex.