Tham Lot cave (Thai: ถ้ำลอด) is a cave system with a length of 1,666 meters near Sop Pong in Pang Mapha District, Mae Hong Son Province, northern Thailand. The Nam Lang River flows through the cave which is filled with stalactites and stalagmites. The cave is home to large numbers of bats and swifts. In Tham Lot and other caves nearby teakwood coffins have been discovered which are thought to have been carved by the Lawa tribes people thousands of years ago.

Another cave in the area, the second longest known cave in Thailand, is Tham Mae Lana, which is 12 kilometres long. This was explored by Australian expeditions between 1984 and 1986. Other caves in the area which are over one kilometre long include Tham Nam Lang (8,550 m), Tham Bung Hu (4,442 m), Tham Pha Mon (4,050 m), Tham Seua/Tham Lom (3,100 m), Tham Susa (2,617 m), Tham Huai Kun (1,747 m), Tham Pang Kham (1,370 m) and Tham Plah (1,365 m). Spirit Well (Nam Bua Phi), a large collapsed sinkhole, one of the largest known natural holes in Thailand, is south of the Hwy 1095. It is more than 200 m across and 90 to 130 m deep. It was first descended, by Australians, in 1985.

• List of caves
• Speleology

• "Karst and Caves of the Nam Lang - Nam Khong Region, North Thailand" John R. Dunkley (1985) Helictite Vol. 23 No. 1 pp3-22
• "Expédition Thaï-Maros 85" Louis Deharveng (ed.) (1986) Association Pyrénéenne de Spéléologie, Toulouse ISBN 2-906273-00-7
• "Expéditions Thaï 87-Thaï 88" Louis Deharveng (ed.) (1988) Association Pyrénéenne de Spéléologie, Toulouse ISBN 2-906273-02-3
• Caves of Thailand John R. Dunkley (1995) ISBN 0-9589253-9-9 pg1-44

Media related to Tham Lot at Wikimedia Commons 19°34′19″N 98°16′38″E / 19.57194°N 98.27722°E / 19.57194; 98.27722