Kathun Reservoir

Kathun Reservoir (locally คลองกะทูน, “Klong Kathun”) sits in Kathun subdistrict, Phipun district, about 30 minutes’ drive from central Nakhon Si Thammarat. It’s a royally-initiated dam project — built after a 1988 storm triggered flash floods and mudslides that destroyed roughly 1,500 homes in the subdistrict — completed in 1997 to help control flooding along the Tapi River basin. Entry is free, and the site is open daily from around 6am to 6pm.

The reservoir holds about 70.5 million cubic metres of water across more than 12,500 rai, backed by the hills of the Nakhon Si Thammarat mountain range. Locals call it the “Switzerland of the South” for the way the green ridgelines rise straight out of the water — most striking early in the morning during the cool season, when a low mist sits over the surface before it burns off. The dam and shoreline give walkable views across the lake toward the hills; fishermen cast from the banks and small boats work the water, and the Royal Irrigation Department still manages it as a working flood-control and irrigation reservoir for the surrounding farmland, not solely a tourist site.

Insider Tip: Go early morning in the cool season (roughly November to February) for the best chance of mist over the water and the coolest temperatures for walking the dam.

There’s no built-up visitor infrastructure — a handful of shaded picnic spots, but no restaurant strip or gift shops — so bring your own food and water if you’re planning to stay more than an hour or two. The pace here is genuinely local: fishing and quiet afternoons rather than organised activities.

Watch out: Facilities are minimal and there’s no lifeguard or marked swimming area — this is a working reservoir, not a managed beach.

If you’re touring Nakhon Si Thammarat’s inland nature spots, pair this with Khao Nan National Park or Tha Phae Waterfall elsewhere in the province.