Tharnsadet means "river of visited by Royals" and it is the place where King Churalongkorn, The Great Rama V came to many times to walk up the wondrous waterfalls and bath in its pools. King Prajadhipok, the Great Rama VII also visited as has the current King Bumipol Aduldej, the Great Rama IX.

Tharnsadet has recently been declared a National Park due to its great historical importance and abundant wildlife. Tharnsadet Beach is small-sized one from Tharnsadet Waterfall through the sea. Beach is white and good enough for swimming. The waterfall are more like huge stepping stones and can be approached from numerous places either from the magnificent beach of Haad Tarnsadet or on the road into Tharnsadet. Not far from the waterfall the river empties into the sea at Than Sadet Bay, with its sandy beach another popular place within the park.

• Accessing here is recommended by experienced motorcyclists only or hiring a jeep or a boat.
• Visitors can take a train from Bangkok to Surat Thani Railway Station, then take a connecting bus to Samui
• Bus: Visitors can also get to Ko Samui by bus from Bangkok (loaded onto a ferry at Don Sak). Bangkok-Ko Samui buses depart from Bangkok 's Southern Bus Terminal at 19.30 daily. Travelling time is 13 hours.