The Tigris River flows through this capital

In troubled Venezuela many have scoured the polluted waters of the Quaire River in this capital in search of anything of value

Of the 4 capitals that stand on the Danube 3 start with a B: Bratislava Budapest & this one further south

A tributary of the Rhine the Aare River wraps around this city on three sides in a canton of the same name

This capital of Laos lies on the Mekong