Khao Yai National Park

Where it sits. Khao Yai spans the western end of the Sankamphaeng Range, the escarpment that separates the central plains of Thailand from the Khorat Plateau, about 120 kilometres northeast of Bangkok. The park covers roughly 2,168 square kilometres across four provinces — Nakhon Ratchasima, Saraburi, Prachinburi and Nakhon Nayok — and rises from around 400 metres on its lower slopes to 1,351 metres at Khao Rom. That altitude range produces an unusual stack of habitats within a short distance: dry evergreen forest on the lower ground, moist evergreen forest through the middle band, and grassland and hill evergreen forest on the high plateau, with rivers that feed four major watersheds including the Nakhon Nayok and the Lam Takhong.

The story behind it. Khao Yai was declared Thailand's first national park in September 1962, the founding act of the country's protected-area system. Before that, the plateau held a settlement of several hundred households that was cleared during the 1930s; the name means simply "big mountain". In 2005 UNESCO inscribed Khao Yai as part of the Dong Phayayen–Khao Yai Forest Complex, a chain of five protected areas running 230 kilometres east to the Cambodian border, recognised as one of mainland Southeast Asia's most important remaining blocks of contiguous forest. That contiguity is the point: it is large enough to support wide-ranging animals that cannot survive in fragments.

The wildlife. Around 300 wild Asian elephants live in the park, and encountering one on the park road after dark is a routine and genuinely dangerous event — rangers post rules about switching off engines and reversing slowly. Gaur, sambar, barking deer, wild pig and pig-tailed macaques are common; leopards and clouded leopards are present and rarely seen; the tiger population is considered functionally lost from this park, a sobering detail for a site of this size. Two gibbon species, white-handed and pileated, call across the canopy at dawn from a range where they overlap and hybridise. Four hornbill species breed here, including the great hornbill, whose wingbeats are audible from a long way off, and the park is a well-known site for Siamese fireback and coral-billed ground cuckoo. Watchtowers at the Nong Phak Chi salt lick and at Mo Singto give the reliable large-mammal viewing; night safaris on open trucks run from the visitor centre.

On screen. The park's best-known waterfall, Haew Suwat, is the 20-metre drop that Danny Boyle used in The Beach in 2000 for the sequence where Leonardo DiCaprio's character jumps from the lip into the pool below — the only major part of that production filmed away from the Andaman coast. It is a genuinely photogenic curtain in a rock amphitheatre, and it is reached on a short path from a car park, which is why it draws more visitors than anything else in the park. The far bigger Haew Narok, in the south of the park, falls in three tiers for a combined 150 metres and needs a longer walk and a lot of steps. It also carries a grim recent history: in 2019 a herd lost eleven elephants over the falls in a single incident while crossing the river above it.

What you actually see today. The park has a proper road network, several campsites and bungalows, and a set of marked trails ranging from 20-minute loops at the visitor centre to a six-kilometre route between Kong Kaeo and Haew Suwat that requires leech socks in the wet season. Wang Chang Rong and Pha Kluai Mai are smaller falls with good swimming. Pha Diao Dai is a clifftop viewpoint on the southern rim, best in the late afternoon with the Prachinburi plain below. Outside the park boundary on the Pak Chong side, the valley has become Thailand's principal wine region, with vineyards such as GranMonte and PB Valley producing what the trade calls new-latitude wines from Chenin Blanc, Syrah and Durif, alongside a heavy build-out of resorts and theme cafes along Thanarat Road.

Getting there and timing. Pak Chong, on the northeastern railway line and about three hours from Bangkok by train, is the usual base; songthaews and taxis run the 30 kilometres to the northern gate. Coming from Bangkok by car takes two and a half to three hours via Highway 2. Foreign visitors pay a higher entrance fee than Thai nationals. The cool dry season from November to February is the most comfortable and the busiest, with weekends heavily booked; September to November puts the most water over the falls; March to May is hot and hazy; June to October brings leeches, mud and closures on some trails. Main viewpoints and the visitor centre are reachable by vehicle, but the trails and waterfall staircases are not accessible.