Erawan National Park is a 550 km2 park in western Thailand in the Tenasserim Hills of Kanchanaburi Province, Amphoe Si Sawat in tambon Tha Kradan. Founded in 1975, it is Thailand's 12th national park.
The major attraction of the park is Erawan Falls, a waterfall named after the erawan, the three-headed white elephant of Hindu mythology. The seven-tiered falls are said to resemble the erawan. There are four caves in the park: Mi, Rua, Wang Bahdan, and Phartat. Rising northeast of the waterfall area there is a breast-shaped hill named Khao Nom Nang.
Erawan Waterfall is located in the east side of the park. The entire length of the seven tiers span approximately 1,500 m through the thick rainforest of the park. Each of the steps has its own name.
The first waterfall – Lhai Keun Lung, is relatively easy, as you can get there on a flat trail, directly from the visitor centre’s car park. The highlight of this first waterfall is the great number of fish swimming in the ponds formed by the smooth limestone sculpted by the water.
The second waterfall – Wang Matcha, is usually busier with swimmers. It’s very scenic as there’s a small cave under the falls.
The third waterfall – Pha Nam Tok, this tier is taller than the first two falls (about 20-metre high), and offers a large pond again filled with fish where you can refresh yourself.
The fourth and fifth waterfall – Oke Nang Phee Suer and Buer Mai Long, feature small cascades and ponds surrounded by rock formations and dense vegetation.
The sixth waterfall – Dong Pruek Sa, is where the trail gets rougher after the fifth tier, and you have to use rickety ladders and ropes to progress through even thicker lush vegetation. The sixth tier is another multi-tiered cascade featuring a wide plunge at the foot. It takes some more effort to reach the seventh tier of Erawan Waterfall, as the last stretch of the trail is particularly challenging. The seventh waterfall - Phu Pha Erawan is the last fall featuring three steps that give their name to Erawan Waterfall. In fact, Erawan is the name of a three-headed Hindu God. It roughly takes three hours to explore the total length of the fall and see all seven tiers.

Source: Wikipedia