Than Sadet-Ko Pha-Ngan National Park

Than Sadet–Ko Pha-ngan is a national park in southern Thailand, with an area of 26,866 rai ~ 43 km2: 132  mostly on the island Pha-ngan. The park was established on 22 November 2018. It covers parts of the 65 km2 Ko Pha-ngan island.

The park is named after the royal visit of Rama V, Than Sadet who came to the island to visit the waterfall first in 1888, then returned as many as fourteen times over the next 21 years. Rama V's initials can still be seen carved in a commemorative rock near the estuary of the river where the waterfall empties into the sea at Than Sadet Bay. The river itself forms a series of waterfalls and rock pools along its 2.5 km length, providing excellent trekking possibilities for the experienced. Several other Thai monarchs have visited the site including the late King Rama IX.