This lovely waterfall, also known as Nam Tok Khao Pang, is a very popular place for Thais, who flock here at the weekends to have a swim and roll out their sitting mats for a picnic in the tree-shaded grounds. You can also see a WWII-era Japanese steam train parked here.
It's 1.5km northwest of Nam Tok's train station, signposted north of Hwy 323, or you can just walk along the train tracks.
Up above the falls, 100m straight back from the dam, is little Tham Sai Yok (8am to 5pm). Two Buddha images are lit up by natural light while at the back is a holy snake-shaped rock you can only see if you bring a torch.
Although this is part of Sai Yok National Park, no fees are collected.