Muang Kao

in Wat Phu World Heritage Area

Where the road to Wat Phu turns away from the Mekong, the remains of the Champasak's ancient city ('Muang Kao') begin. Founded in the mid-5th century by King Devanika and lasting for at least three centuries, there are pre-Angkorian walls (both earthen and brick) and other mostly still-buried remnants spread across the nearly 4-sq-km site. But, though you pass right through the heart of it on your way to Wat Phu, you can't see anything ancient from the road.

There's a map of the many ruins just south of the bridge on the site's river side, but you'll need a guide if you want to explore it properly. And probably only serious history buffs will get anything out of the experience.