Khao Yai National Park covers an area of over 2 000 square kilometers and includes one of the largest intact monsoon forests in mainland Asia. Consider by many to be among the best national park in the world, Khao Yai was recently designated an ASEAN national Heritage Site.

The park encompasses a wide variety of habitats, including sub-mountain evergreen forests and grasslands. There are also several mountains of around 1000 meters including Khao Khieo. Host to almost 2 500 plant species, 67 different kinds of mammals and over 300 species of birds. Some 200 to 300 wild elephants reside within the park boundaries, other recorded mammals include sambar deer, barking deer, gaur, wild pig, Malayan sun bear, Asiatic black bear, tiger, leopard, serow and various gibbon and macaques. In general these animals are easily spotted during the rainy season from June to October. Khao Yai also has Thailand largest hornbills, including the great hornbill, king of the bird kingdom, as well as wreathed hornbill, indian pied hornbill and rhinoceros hornbill. Hornbills breed from January to may, the best time to see them. They also feed on figs, so ficus trees are good places to find them. Caves in the park are home to rare wrinkle-lipped bats and Himalayan ribbed bats.

The entire area is criss-crossed by over 50 Km of hiking trails, ranging in length from one and a half to eight kilometers (see below). There are also three wildlife-watching towers in the park. There are in addition many waterfalls, the tallest and most spectacular of which is Haew Narok at 80 meters.

HIKING TRAILS

Active travellers who like to explore deep into the forest can choose one of 13 trails at Khao Yai. Note that some trekking route should be guided by experienced forestry officials

1 - Kong Kaew-Heo Suwat:
The eight-kilometre trail starts from the back of the visitor centre. Cross Lam Ta Khong and follow the red paint markers on the trees. Gibbons can be observed. A trail off to the right goes to Pha Kluai Mai, and one on the left to Pong Chang. A guide is needed.

2 - Kong Kaew-Pong Chang II:
The six-kilometre hike takes four to five hours. Follow Trail 1 to the turnoff for Pong Chang, then follow the blue markers on the trees. Sometimes the signs can be confusing. A guide is needed.

3 - Kong Kaew-Pha Kluai Mai:
The six-kilometre hike takes three to four hours. Follow Trail 1 to the turnoff, then follow the yellow markers on the trees. If starting from Pha Kluai Mai, the entrance to the trail is on the left of the road to Heo Suwat, 300 metres from the campsite.

4 - Pha Kluai Mai-Heo Suwat:
The three-kilometre trail takes about 90 minutes. From Pha Kluai Mai, look for the sign to Heo Suwat. From Heo Suwat, the trail starts near the toilet.

5 - Heo Suwat-Thung Ya Khao Laem:
Go upstream along Lam Ta Khong until the bridge and proceed to Thung Ya Khao Laem. The trail is three kilometres long and requires at least two hours. This trail should be guided.

6 - Park office-Nong Phak Chi:
Start opposite the food stalls and follow the signs along the four-kilometre trail to Nong Phak Chi. From here, follow the dirt road for one kilometre to a paved road and walk two kilometres back to the park office. This trail is very popular.

7 - Park office-Wang Cham Pee:
Follow Trail 6 to the first turnoff, go right and then go right again at the next turn. Continue until you reach the highway at Km 36. It is one kilometre to the park office. The circular route takes a few hours.

8 - Kong Kaew-Golf Course Road:
Start at the back of the visitor centre and stay parallel to Lam Ta Khong stream. The easy 1.5-kilometre walk is ideal for early-morning birdwatching.

9 - Park office-Mor Sing Toh:
Follow Trail 6 and turn left at the first crossroads. The trail leads to an open meadow and a reservoir at Mor Sing Toh. Allow two hours.

10 - Park office-former TAT restaurant:
Follow Trail 6 and turn right at the first crossroads. At the second crossroads, turn left. This six kilometre trail requires a guide.

11 - Old TAT restaurant-Tat Ta Phu waterfall:
The trail follows the stream to the waterfall, with the return trip taking a full day. A guide is required.

12 - Dan Chang-Bueng Phai:
Start at Km 32 and proceed for 1.5 kilometres.

13 - Nong Pak Chi-Khlong Ee-thao:
This four-kilometre hike sets off from the Nong Phak Chi wildlife observation tower.