Pang Sida National Park

Pang Sida covers around 844 square kilometres on the southern side of the Dong Phayayen-Khao Yai Forest Complex, connected to Thap Lan and ultimately to Khao Yai, and it is inscribed as part of that UNESCO property. Its best-known feature is seasonal: from roughly May into July, large numbers of butterflies gather on damp mineral-rich ground along the park roads and streams in a behaviour called mud-puddling, where males take up salts and minerals from wet soil. Hundreds can settle in one patch, and the park runs a butterfly festival around it. There are also waterfalls - Pang Sida and Pha Takhian - and forest holding elephants, gaur and a small tiger presence monitored across the complex, though sightings are rare. Facilities are basic with camping and simple bungalows. Roads inside the park are rough and some sections close in the rains, and the butterfly season overlaps with the start of the wet.

What you actually see

• The mud-puddling butterflies - hundreds gathering on damp ground, May to July.
• The waterfalls - Pang Sida and Pha Takhian on the park streams.
• The UNESCO complex - the southern end of the Dong Phayayen forest.
• The quiet - very few visitors compared with Khao Yai.

When to go

May to July for the butterflies, which is the reason most people come; November to February for the most comfortable weather. Roads are difficult in the heavy rains.

Honest expectations

Basic facilities and rough internal roads. Butterfly numbers vary year to year and are weather-dependent. Large mammals are present but rarely seen. Foreign entry fees are higher than Thai.

Nearby

Lalu earth pillars are east; Thap Lan National Park is north.