The pagoda(s) are located in My Duc hamlet in the province of Ha Tay. According to the book, Huong Son Thien Tru Pha, Huong Tich temple was built during the reign of Le Chinh Hoa (1680-1705), by a monk who happened on the site on his way to search for enlightenment. Other shrines and temples were later built in this area to take advantage of the beautiful scenery in this area.

Source: http://handetour.com/Vietnam-Travel-Guides/Vietnam-Attraction/vietnam-pagoda-and-temples.html