The Gauja river is the longest river in Latvia, starting in the Vidzeme Highlands and ending at its meeting point with the sea in Carnikava. The Gauja circles the Vidzeme uplands in a wide curve, highlighting sandstone cliffs with caves, while downstream its bed is sandy, its bends are steep, and its banks are in many places eroded.

Gauja is the most popular navigable river in Latvia, especially the stretch from Valmiera to Sigulda, which is full of sights and recreational attractions. In terms of water tourism, the Gauja can be divided into three sections: the HPP cascade section, the popular section and the downstream section.

The river is navigable all year round, unless frozen.

Total length 452km, drop 234m.