Introduction to the Undersea Tunnel: It is more than 100 meters long and consists of a polygonal tunnel with 90-degree and 180-degree viewing windows. Nearly a thousand species of marine life such as silver pomfret, black-backed ray, Sichuan flute, cobia, sagefish, spiny-tailed blue tang, giant crab, spotted lip-lipped shark, and cowport trevally are within reach; making people enter this area , there is a feeling of melting into the ocean.