Khao Sok National Park, in the Surat Thani province of Thailand, is the largest pristine forest in the area and is a small part of a rainforest that in yesteryears was bigger and denser than the Amazon rainforest. Rich and diverse in flora and fauna, the park is one of the best places to witness rare species such as Rafflesia flower, hornbill birds, gibbons and tigers. Punctuated by limestone cliffs, mountains, splendid sandstone and mudstone rocks, this is the wettest part of Thailand.