Erawan National Park, Kanchanaburi

Erawan is the best-known waterfall in Thailand and the reason most visitors go north-west from Kanchanaburi. It falls in seven distinct tiers over about two kilometres of forested valley, and because the water is heavy with dissolved limestone it deposits travertine as it goes - which is what gives the pools their opaque blue-green colour and their smooth rounded lips.

A path follows the stream from the park entrance to the top, getting rougher with each level; the lower tiers are an easy walk, the last two involve scrambling. Most of the pools are open for swimming and hold shoals of fish that will investigate anyone standing still. The seventh tier, the one named for the three-headed elephant Erawan whose shape the rock is said to resemble, takes a good hour and a half to reach.

The park is at its fullest after the rains and can slow to a trickle late in the dry season.