Tam Giang - Cau Hai lagoon system is a world-class brackish water area. It is the largest in Southeast Asia, with special value in biological resources and countless gripping things in history and culture.... This area is seen as a "precious biological gem" that nature has bestowed on the ancient capital. With what existent, is it necessary to build an exhibition space or a museum for the Tam Giang - Cau Hai lagoon system?