Khao Chamao-Khao Wong National Park

Khao Chamao-Khao Wong National Park sits about 65 km from Rayong town, straddling the border between Rayong and Chanthaburi provinces around two forested peaks that give the park its name. Gazetted on 31 December 1975 and covering roughly 52,300 rai (about 84 sq km), it protects one of the last substantial blocks of lowland rainforest left on Thailand’s eastern seaboard — dense enough that rosewood, Burmese ebony and old-growth eaglewood still stand alongside wild orchids and stands of bamboo and rattan.

Two marked trails from the headquarters area at Tambon Thung Khwai Kin cover most of what visitors come for: a 2 km loop taking about an hour, and a longer 3 km route running closer to ninety minutes, both passing through forest thick enough to hide a salt lick used by wildlife and stretches where hornbill calls carry further than the birds themselves are visible. The park is the source of the Prasae River, and its waterfalls — reached off both trails — are the main draw beyond the forest itself, running strongest just after the rainy season from around October through December.

Watch out: Leeches are common on both trails after rain, especially June through October. Long socks tucked into closed shoes make a real difference; sandals do not work here.

Getting in means registering at the visitor centre near park headquarters before setting off — standard practice across Thailand’s national parks, and useful in practice since rangers know who’s out on the trails if weather turns. From Rayong town, the drive follows Sukhumvit Road out to the Khao Din intersection near Km 274, then a further 17 km on the park access road to the headquarters — allow around an hour and a half door to door, longer without your own transport since there’s no scheduled public transport to the gate.

Insider Tip: Visit on a weekday morning if you can. The trails see day-tripper coach groups from Rayong and Pattaya on weekends, and the earlier you’re on the shorter loop, the better your odds of the salt lick and the hornbills that use it actually being active rather than scared off by foot traffic.

Camping gear can usually be rented at the headquarters if you want to stay overnight rather than day-trip it, and a small kiosk sells basic supplies, though it’s worth bringing your own food and water for the trails themselves — there’s nothing sold along either route.

Nearby in the same inland forest belt: Wangchan Forest Learning Center and Samnak Song Namtok Tammarot. Full area guide at Rayong.