Hon Mun has a total area of ​​160 km2, of which 122 km2 is the sea surface area, 38 km2 is the total area of ​​the islands. In the black rock caves of Hon Mun Nha Trang, birds nest every year because the island’s terrain is very close to the hot ocean currents brought by from the equator which is suitable for the development of coral and many types of tropical marine life also gather here. Therefore, Hon Mun has a diverse coral reef and marine ecosystem.

Hon Mun Nha Trang is the first and only marine protected area in Vietnam today, and has been rated as the most marine biodiversity area in Vietnam by the World Wildlife Fund (WWF). Under the sea floor, at a depth of 10m, is the gathering place of coral reefs with a variety of colorful and variety fish.

According to statistics, the world has about 2,000 species of coral and marine life. Yet, in Hon Mun, there were 1,500, in which, 340 out of 800 species of hard corals in the world have been found. With a depth of less than 18m, there are no beautiful views of the coral but there are many caves. There are caves 10 – 15m deep so visitors have to use light to observe. Among them are marine creatures that live in the dark such as shrimp, squid, lobster, rays, etc.

If you have a talent for scuba diving, you will admire the immense coral forests on the bottom. Along with are beautiful coral flowers and exotic sea creatures.