Thi Lo Su Waterfall

Thi Lo Su is a large multi-tiered waterfall in Tak province, northwestern Thailand, located within the Umphang Wildlife Sanctuary. It is widely regarded as Thailand’s largest waterfall by volume and scale.

The main drop and adjacent cascades form a broad, curtain-like fall with a near-vertical drop and extensive sheet flows; commonly cited dimensions put the tallest drop at around 250 metres and the cascade width at several hundred metres at peak flow. Visitors are drawn by the extensive water flows, boardwalk viewpoints and the surrounding rainforest. The falls are most dramatic in the rainy season when tributaries swell and the curtain of water broadens.

Thi Lo Su lies deep inside the Umphang Wildlife Sanctuary and is reached after travel into Umphang district followed by a further off-road transfer and walk into the sanctuary. The site is protected and access arrangements vary seasonally to manage visitor impact and seasonal conditions.

The waterfall sits in dense forest in northwest Tak province near Thailand’s border with Myanmar, within the protected area of Umphang. The surrounding landscape is steep, forested and mountainous, and the falls are remote compared with major tourist centres.

• Best time to visit: Water flow is highest during and shortly after the monsoon, typically between July and October, when the falls are most impressive.
• Access and permits: Access requires travel into Umphang district and a further journey into the protected Umphang Wildlife Sanctuary; local guides or park arrangements are commonly used for the final approach.