River Spree is the name given to the river that cuts through both Unterganger City's Old Town and Athyras's Historical District. It was named after the Spree River that flows through Berlin. The river is generated in a loop - both ends empty into the Burgy Sea.

Extensive development on its banks saw the river widened and shrunk at places, and its courses straightened with right angle turns (particularly in Athyras's side) or gently curved (in part of Old Town).

The river is the venue of the River Spree Boat Race. Along the banks directional signs are placed, particularly around corners, to guide racers.