Erawan Falls is a seven-tier waterfall climbing about 1,500 metres of forested hillside in western Thailand. Each tier holds its own pool of milky emerald water: some shallow and glass-clear over pale rock, others deep enough to swim in, with low natural dams of stone between them. The colour comes from limestone dissolved in the stream — no algae, no dye. The falls take their name from Erawan, the three-headed white elephant that Hindu myth gives the god Indra to ride, and the topmost tier is said to echo the shape of its head. The whole staircase lies inside Erawan National Park, set aside in 1975 as Thailand's twelfth, 550 square kilometres of the Tenasserim hills about three hours west of Bangkok.
A marked path threads about two kilometres up alongside the seven tiers, climbing from one pool to the next. Wade into the water and small garra fish drift over to nibble at your feet, while macaques work the branches overhead and open any bag left unguarded. The forest around the falls shelters some 120 bird species, among them great hornbills that cross the high canopy on heavy wings. In September, when the heaviest rain turns the upper trail dangerous, swimming is suspended and the top tiers close, though the lower cascades can usually still be walked to. Climb slowly and the falls change as you go: the roar of the lower cascades gives way to birdsong, the canopy tightens overhead, and by the seventh tier the forest feels like your own.