Thay Pagoda is a group of pagodas at the foot of Sai Son mountain, Quoc Oai district, former Ha Tay province, now Sai Son commune, Quoc Oai district, Hanoi, about 20 km southwest of Hanoi center and follow Lang - Hoa Lac highway. Sai Son named Nôm is Thay mountain, so it is called Thay pagoda. The pagoda was built during the Dinh dynasty. This used to be a place of practice for Zen master Tu Dao Hanh, at this time, Thay's mountain is also called Buddha Tich mountain.
At first, Thay Pagoda was just a small temple called Huong Hai am, where Tu Dao Hanh Zen master was based. Ly Nhan Tong King built two temples: Cao pagoda (Dinh Son Tu) on the mountain and the lower temple (ie Ca pagoda, the name is Thien Phuc Tu).