The Erawan National Park was designated in June 1975 as Thailand's 12th national park. It covers an area of 550 km² of high mountains and valleys. The eastern mountains rise to nearly 1,000 meters with shear limestone cliffs. These mountains protect the area from the eastern monsoon resulting in a low average rainfall. In summer the weather is sweltering, but it is cool between November and February. The main feature of the park is the stunning 7 tired Erawan waterfall.