Many believe this lowland jungle – the wettest spot in Thailand – to be over 160 million years old, making it one of the oldest rainforests on the globe.

It features dramatic limestone formations and waterfalls that cascade through juicy thickets drenched with rains and morning dew.

this is what the website about Khao Sok says:

http://www.khaosok.com/

Khao Sok National Park in Southern Thailand is an amazing place. It is covered by the oldest evergreen rainforest in the world, huge limestone mountains shooting straight up in the air, deep valleys, breathtaking lakes, exciting caves, wild animals and much more.

there are also the largest flowers in the world:

Rafflesia are the largest flowers in the world, and can grow up to 90cm in diameter. The largest species Rafflesia arnoldii does not grow in Thailand, but there are three other species that do grow here. The flower is like a giant red bowl lined with yellow spotted petals. The flowers exude a strong smell – similar to the smell you would expect to find near a rotten carcass or a dustbin. The reason is that these flowers are not pollinated by insects seeking nectar; it is believed they are pollinated by flies. The Rafflesia are endoparasites and require the presence of Tetrastigma (wild grape vine) hosts, without which they do not grow. The Rafflesia got its name from the leader of the expedition, who discovered the first flower in Indonesia in 1818; Sir Thomas Stamford Raffles. The Rafflesia is the official flower of Surat Thani province. Rafflesia are becoming increasingly rare due to habitat losses and collection by human beings.

the visit was very amazing and inspiring to see such natural beauty here are some pictures.enjoy and if you are around Thailand try to visit.....