Pha Diao Dai Cliff is one of the most famous natural viewpoints in Khao Yai National Park, located along the route leading to Khao Khiao Peak, the park’s highest point. Situated at approximately 1,292 meters above sea level, the area enjoys cool temperatures throughout the year, especially during the rainy and winter seasons, when thick mist often blankets the surrounding forest in the early morning.

The name “Pha Diao Dai” roughly translates to “The Lonely Cliff,” referring to the large rocky cliff that stands prominently above the vast forest landscape. From the viewpoint, visitors can enjoy sweeping panoramic views of the Dong Phaya Yen mountain range and the forested areas connecting Nakhon Nayok and Prachin Buri provinces. On clear days, layers of mountain ridges stretch endlessly across the horizon, while sunrise transforms the landscape into a stunning scene of golden light, drifting fog, and lush green forest.

This area is part of the Dong Phaya Yen–Khao Yai Forest Complex, which was designated as a UNESCO World Natural Heritage Site in 2005. The forest plays a crucial ecological role as a watershed and wildlife habitat, containing one of the richest montane rainforest ecosystems in central Thailand.

The Pha Diao Dai Nature Trail is approximately 450 meters long and designed as a circular walking route. The national park has constructed an elevated wooden boardwalk to allow visitors to explore the forest safely while minimizing environmental impact. Along the trail, visitors will encounter large native trees covered in mosses, ferns, lichens, and dense green vegetation typical of humid montane forests.

One of the most remarkable features of the trail is the enchanting moss forest atmosphere. Thick layers of moss and moisture-loving plants cover tree trunks, rocks, and fallen branches, creating scenery that resembles an ancient fantasy forest. After rainfall, thin mist often drifts through the trees, making the area especially beautiful for photography and nature observation.

Pha Diao Dai is also an excellent destination for birdwatching and wildlife observation. Visitors may spot species such as the Great Hornbill, broadbills, sunbirds, squirrels, civets, and barking deer, particularly during the quieter hours of the morning and evening. During the rainy season, various species of wild mushrooms emerge throughout the forest, reflecting the richness of the ecosystem.

The best time to visit is between October and February, when temperatures are cooler and the sea of mist is at its most impressive. Early morning temperatures can occasionally drop below 15°C. During the rainy season from June to September, the forest becomes exceptionally green and humid, with mist lingering throughout much of the day, making it ideal for nature photography and ecological exploration.

Although the trail itself is relatively short, the cliff area can be steep and windy. Visitors should follow park regulations carefully, remain within designated boundaries, and avoid making loud noises that may disturb wildlife.

More than just a viewpoint, Pha Diao Dai Cliff offers an immersive experience within one of Thailand’s most important rainforest ecosystems. It is an ideal destination for travelers seeking fresh mountain air, peaceful natural surroundings, scenic hiking, sea of mist views, and a deeper appreciation of Khao Yai’s World Heritage forest landscape.

• From the Khao Yai National Park Visitor Center, drive toward Khao Khiao Peak along the paved mountain road for approximately 12–14 kilometers. The entrance to Pha Diao Dai Nature Trail will be on the left side of the road, with parking spaces and park staff available nearby.

• Visit early in the morning for sunrise and sea of mist views

• Wear shoes with good grip, especially during the rainy season

• Wooden walkways and cliff areas may become slippery after rain

• Stay within the designated trail and safety barriers

• Bring a light jacket, as temperatures are cool year-round

Admission Fee:

Thai Visitors

• Adults: 40 Baht
• Children: 20 Baht

Foreign Visitors

• Adults: 200 Baht
• Children: 100 Baht

(The fee covers entry to Khao Yai National Park and allows access throughout the park.)

Opening Hours:

• Open daily from 06:00 AM – 05:00 PM

• Note: The trail may be temporarily closed during heavy rain periods for visitor safety and forest restoration purposes.