Thailand‘s topography varies: High mountains, predominantly cover-ed with large rainforests, are in the N and in the W along the border to Myanmar. Limestone caves are found in the mountains through-out Thailand. The vast Khorat Plateau in the N-E (about 300m above sea level) has poor soil and is bordered by the mighty Mekong river. The capital Bangkok lies in the fertile central region that is watered by the Chao Phraya river just before it drains into the Gulf of Thailand. Some of Thailand‘s hundreds of islands ascend like huge boulders from the sea and have spectacular rock formations. Thailand‘s coastline and the islands are mostly covered by coconut palm trees and have sandy beaches.