Here’s a detailed overview of Hồ Trị An (often called Tri An Lake) in Đồng Nai Province — including what it is, why it’s special, and what you should know if you plan to visit. What and where The lake is a large artificial reservoir on the Sông Đồng Nai (Dong Nai River), in Đồng Nai Province. It spans the administrative boundaries of the districts: Huyện Vĩnh Cửu, Huyện  Định Quán, Huyện Thống Nhất and Huyện Trảng Bom. It covers about 323 km² (which is about 32,000 + hectares