The Bolaq is a narrow canalised stream that runs north-south through the centre of Kazan, dividing the old Russian upper town from the Tatar lower town. Once a major waterway connecting the Volga to Lake Kaban, it was reduced over the 19th and 20th centuries to its present form — a stone-banked channel just wide enough for a footbridge to span in a couple of strides.
The walk along the Bolaq is the most direct way from the centre to the Old Tatar Quarter. Footbridges cross at intervals of every couple of hundred metres. Several of the more interesting older houses on either bank are former merchant dwellings now repurposed as cafes and small museums.