Near the Cambodian border, the forests of eastern Thailand are some of the wildest in the country, and Dong Yai is part of a great chain of them. The Dong Phayayen–Khao Yai forest complex, which UNESCO listed in 2005, covers about six thousand square kilometres of hills and valleys stretching from Khao Yai National Park to the Cambodian frontier. Dong Yai Wildlife Sanctuary is one of the five protected areas in the complex, together with Ta Phraya, Thap Lan and Pang Sida National Parks, and it forms a corridor for animals that need space.
The forest is home to elephants, gaur, sambar deer, leopards, and, though rarely seen, tigers, as well as Asian black bears, gibbons and an extraordinary range of birds, including several species of hornbill. This is one of the few places in Thailand where wild elephants still move in large numbers between protected areas. Most of the sanctuary has no public facilities, and access is limited, but the surrounding country gives a taste, with hills covered in dry evergreen and bamboo, and a thin population of farmers growing cassava, maize and rice.
For a rider, the roads in this part of eastern Thailand are typically smooth, well marked and quiet, with long straight sections and gentle rises. The famous road through Khao Yai National Park, to the west, is a winding mountain route with wildlife on the verges, and it is wise to ride slowly, since elephants and deer cross at night, and the park has strict speed limits. The cooler dry season, from November to February, is the best time for riding and wildlife watching, while the rainy season brings heavy showers and wet roads. In the border region, there are military checkpoints, and you should carry your passport and licence.
Soeng Sang, about twenty-eight kilometres away, is a small town with fuel, shops and noodle stalls, and the larger town of Pak Chong, on the Khao Yai road, has more choice. Thai roadside food is generally superb and cheap, and small stalls selling grilled chicken and sticky rice are often better than hotel restaurants. Carry water, wear a hat, and keep to marked roads, because the border area has landmines in places, as a legacy of old conflicts.