that the first Aquarium Center in the Southeast Asian region with a large underwater tunnel and longest in the world. It collectsthe freshwater fishes from the Meakhong River and the sea to be interdependent living. Chiangmai Zoo Aquarium is a new attraction, and is aquariums centers of Asia and the world in the future. The project area is 10Rai, and the area ofaquariumexhibition building is​13,985 square meters. There is aunderwater tunnel in the building which is a freshwater and a sea tunnel and linked together by auto-walking way and is the longest in the world and total length is 133 meters. The sea tunnel length is 66.5 meters and the freshwater tunnel is 66.5 meters which is the longest in the world. The tunnel is made from clear acrylic which thickness is more than 2.5 inches and can get water pressure at a depth of 5 meters safely. There is exhibition of the aquatic species both the freshwater and sea animals. It exhibits the important of the aquatic species from the rain forests of the world both Asia and Amazon.