Caves of Nanumanga, an underwater cave located in Nanumanga, Tuvalu near Polynesia. In 1986, two scuba divers discovered the caves. Nanmanga caves are located at 37 to 46 meters below the sea level lying underneath the walls of coral cliff. The walls and the roofs are turned black with coral fragments, which give a hint of the use of fire.
Caves of Nanumanga have a legendary behind its discovery, according to a legend the caves were called as a large house under the sea, which led to expedition by the scuba divers and the caves are also known as Fire Caves of Nanumanga. The caves have been submerged deeply underneath the ocean due to continuous change in sea level. Various theories have been laid in accordance to the presence of the caves beneath the water after the discovery of these caves.