Located 10 kilometres east of Lam Nang Rong Dam in Ban Santi Suk, Lahan Sai district, this Potholes Park features Thailand’s largest group of potholes. There are more than 16 large natural potholes in the rocky ground. Their width varies from 40 centimetres to 3 metres with a depth of between 2.5 and 14 metres. It is postulated that the area was an ancient riverbed, 150 million years ago, during which these potholes were formed by pebbles which were transported by water and left on the bedrock. After spinning around for a long time, the pebbles ground away the bedrock thus forming potholes.