Thung Prong Thong

Thung Prong Thong is a wooden boardwalk through a stand of Ceriops mangrove at the mouth of the Prasae River in Klaeng district, Rayong — on the Gulf of Thailand coast, not the Andaman side. “Prong” is the mangrove species; “thong” means gold, and the name describes what happens to the leaves in low sun, not a grassland or savanna. Entry is free, open daily 06:00-18:00.

The colour is the whole point of the visit, and it’s a lighting effect rather than a plant that changes with the seasons. When the sun sits low — early morning or the last couple of hours before sunset — it hits the Ceriops leaves at an angle that turns them a warm yellow-gold across the whole stand. At midday the same trees look like an ordinary green mangrove forest. If you show up at noon expecting the postcard shot, you’ll leave disappointed; time the visit around the light, not the calendar.

Watch out: Midday visits miss the effect entirely — this is a golden-hour attraction, not an all-day one.

The boardwalk itself is a level wooden walkway winding through the mangrove roots, a 20-30 minute walk at an easy pace with a couple of raised viewing platforms along the way. Below the boards, fiddler crabs and mudskippers work the exposed mud at low tide, and egrets and kingfishers use the mangrove edge as a hunting perch. For a longer look at the river mouth, local boat operators run short tours out through the channel to where the Prasae meets the Gulf, priced separately from boardwalk entry.

Insider Tip: Check the tide table before you go — mangrove mudflats look and smell better at low tide, when the crab and mudskipper activity is easiest to see from the boardwalk.

Bring sun protection and water; there’s limited shade once you’re out on the open sections of boardwalk, and Rayong’s coastal humidity makes the walk warmer than it looks in photos. Combine the visit with the nearby Pak Nam Prasae community tourism area for seafood and boat trips, or head back toward Mae Phim Beach for the afternoon.