Some 7km northwest of Thong Pha Phum town, this whopping 92m-high hydroelectric dam creates the Khao Laem Reservoir that stretches all the way up to Sangkhlaburi. From the top of the dam, the glossy indigo views of the lake and the emerald valley below are beautiful, and in the afternoon a troop of monkeys hangs out here. A moto-taxi here and back costs 120B.