Nam Ou

Nam Ou is a major river in northern Laos and an important tributary of the Mekong. It flows through mountainous and karst terrain and is a significant transportation and cultural corridor in Luang Prabang province.

Along its course the river passes limestone karst landscapes, small riverside villages and agricultural valleys popular with multi‑day boat trips and community visits. The confluence of Nam Ou and the Mekong is near the well-known Pak Ou caves, which are commonly visited on Mekong cruises.

Local communities have used the Nam Ou for transport, fishing and irrigation for centuries, and the river corridor has long supported settlements and trade in northern Laos. In recent decades the river has become better known to international tourism through organized boat excursions and trekking routes along its banks.

Flowing through Luang Prabang province in northern Laos, the Nam Ou meets the Mekong just north of Luang Prabang and runs through predominantly rural, hilly terrain before reaching the lowland Mekong valley.

• Confluence with the Mekong: Joins the Mekong near Pak Ou caves north of Luang Prabang, making the river corridor important for river transport and religious sites.
• River trips: Popular for multi‑day river cruises that travel through rural villages, limestone karst scenery and agricultural communities.