Mangrove Arboretum

The Mangrove Arboretum sits on Phet Kasem Road in Ngao subdistrict, on the Ranong mainland — not on Koh Phayam island, despite a name mix-up that sometimes attaches it to the island in older listings. A raised boardwalk runs about 1,500 metres through the mangrove forest, taking roughly an hour to walk, with interpretive signage identifying the different mangrove species along the way. Admission and parking are both free.

The boardwalk keeps visitors dry over ground that would otherwise be impassable mudflat. Mudskippers and fiddler crabs are the easiest sightings at low tide, while kingfishers and herons work the tidal channels overhead. Red mangrove prop roots arch out of the mud in places, and the black mangrove’s pencil-like breathing roots poke up around the base of the trees — one of the clearer places on this coast to see how these species physically adapt to growing in salt water. A small pier near the site also runs boat trips through the mangrove channels, priced as a flat rate per boat rather than per person, which makes it reasonable value if you’re visiting as a group rather than solo.

Insider Tip: Go on a rising tide rather than dead low water — the mudflats smell strongly of sulphur when fully exposed, and the wildlife (mudskippers especially) is more active as the water starts to come back in.

Watch out: This is a nature boardwalk, not a developed attraction — there’s no café or gift shop beyond basic signage, and mosquitoes are a real presence near the mudflats, so bring repellent regardless of season.

Ranong’s stretch of coast falls within the Ranong Biosphere Reserve, UNESCO’s only Thai biosphere designation built around a mangrove coastline, and this arboretum is one of several sites in the area protecting that habitat — the Ngao Mangrove Forest Research Centre closer to Ranong town is a separate, similarly-named site worth knowing apart from this one if you’re trying to find the right boardwalk.

Getting here requires your own transport — a car or rented motorbike from central Ranong, since there’s no dedicated public bus route. It combines well with Raksawarin Hot Springs on the same side of town for a fuller half-day out. For accommodation and the rest of the area, see the Ranong destination guide.