Sai Dam Beach

Thailand’s only black sand beach sits inside a mangrove forest reserve near Laem Ngop pier — the mainland ferry town for Koh Chang, in Trat province, not on the island itself. Hat Sai Dam (“black sand beach”) runs about 1.5 km along a stretch of coast where the dark colour comes from slag and crushed seashell (a form of limonite) rather than volcanic rock, built up gradually within the surrounding Laem Makam mangrove forest. It’s a genuine geological rarity on a coastline that’s otherwise almost entirely white or golden sand.

The turning is roughly 1 km north of Laem Ngop on the road toward Trat town; a concrete access road runs another kilometre to a small parking area and visitor signboard. From there it’s a short walk through mangrove trees — home to fiddler crabs, shellfish, and a decent range of shorebirds — before the black shore opens up. Local folk tradition holds that the mineral-rich sand has curative properties, and a sign at the site explains how to try a foot soak, sand scrub, or a full-body treatment using the sand yourself; this is a self-serve tradition rather than a staffed spa, so don’t expect therapists or treatment tables.

Watch out: Visit at low tide. At high tide the black sand strip narrows sharply and most of what makes the beach worth the detour disappears underwater — check tide times before making the drive from Trat.

The beach draws a trickle of curious travellers rather than crowds, mostly people breaking up the drive between Trat town and the Koh Chang ferry piers rather than making a dedicated trip. There’s no real infrastructure — no food stalls, no shade structures beyond the mangroves themselves — so bring water and reef-safe sunscreen if you’re planning to linger. It photographs well against the mangrove green and any turquoise-water shots elsewhere on your Trat trip, precisely because the contrast is so unusual for Thailand.

Most travellers only pass through Laem Ngop on their way to catch a ferry, which is exactly why this detour works: it’s a 15-20 minute stop that turns dead time waiting for a boat into something worth the memory card space. Combine it with an early or late crossing to Koh Chang and you’ll have the tide timing sorted without extra planning — check the ferry schedule first, then work the beach visit around whichever low tide falls closest to your crossing time.