Pregolya
The Pregolya or Pregola is a river in the Russian Kaliningrad Oblast exclave.Overview
It starts as a confluence of the Instruch and the Angrapa and drains into the Baltic Sea through the Vistula Lagoon. Its length under the name of Pregolya is 123 km, 292 km including the Angrapa. The basin has an area of 15,500 km². The average flow is 90 m³/s.
Euler's Seven Bridges of Königsberg problem was based on the bridges crossing the river in Königsberg.
A possible ancient name by Ptolemy of the Pregolya River is Chronos, although other theories identify Chronos as a much larger river, the Nemunas.- Chernyakhovsk
- Znamensk
- Gvardeysk
- Kaliningrad
Tributaries
- Pissa
- Lava/Łyna
- Angrapa
- Instruch
