Khlong Thom Saltwater Hot Spring is a naturally occurring hot spring. This is different in terms of salty water. There is just one saltwater hot spring in Thailand, according to statistics from its 112 hot springs: Khlong Thom Saltwater Hot Spring. There are only two saltwater hot springs in the world, one in Thailand and the other in the Czech Republic in Eastern Europe. The mangrove forest area of Khlong Bang Phueng and Khlong Pho, Huai Nam Khao Subdistrict, Village No. 8, in Krabi's Khlong Thom District, is home to the Khlong Thom Saltwater Hot Spring. It is a saltwater hot spring with 14 ponds in the region, pure water reflecting the green sky, spanning an area of around  204,360 squaremeters, and releasing a rotten egg odor and a little amount of carbon dioxide (H2S). Green algae and white and yellow calcite crystals were abundant. In the plains, woodlands, and swamps, as well as near Samae and mangrove forests, hot springs can be discovered. It is located in the centre of the valley, between two hills that are 65 meters apart and run north-south. From the ground level, the two hills are roughly 10 meters high. This hill is made up of red conglomerate, brown sandstone, shale, and Jurassic mudstone, with a  ridge of black limestone runs parallel to the hill on the west side. On limestone or near limestone ridges, hot springs can be discovered. This new limestone is assumed to have been produced by the crystallization of calcium carbonate solution.