As you approach the Burmese border at Maesai, the northernmost point of Thailand, the main road meets the western edge of the Shan Plateau rising abruptly from the plain in a series of jagged peaks typical of weathered limestone. These mountains, or karsts, are part of a corderilla stretching from the Himalayan Massive in Tibet down through to the Malaysian peninsular. The geology of this area is one of caves and caverns and underground rivers, many still to be explored but some places are easily accessible to casual visitors. One of these is Wat Tham Pla, an unusual temple complex featuring several caves, nestling at the foot of the mountains 13 kilometres south of Mesai.