In 2009 and 2010 the Shepton Mallet Caving Club visited Ban Mani Phruk in Nan, Thailand. Tham Pha Phueng was explored to a depth of -367m, the deepest known cave in Thailand. Two other caves were explored to depths of -175m (4th deepest in Thailand) and -138m (12th deepest). This report gives full details on the caves explored including surveys and photographs.