Accessible by a short bus ride from Kanchanaburi, Erawan National Park in Thailand features 200 square-miles of limestone hills, forests, steams, flora and fauna. Founded in 1975, its most famous feature (and justifiably so) is the seven-tiered waterfall from which the park derives its name. The waterfall itself is named after a mythological three-headed white elephant that the falls and pools are said to resemble. In any case, the waterfall is truly spectacular and the various pools into which it spills (perhaps gushes is a better word) are great for swimming.
Photo courtesy of Chris Huh via Wikimedia Commons.