The Pearl River or Perlovska River (Bulgarian: Перловска река) is a small river in the Sofia Valley in western Bulgaria. The river is only 17.8 kilometres (11.1 mi) long. It takes its source from the foothills of Vitosha, runs through Sofia's South Park, separates the two lanes of Evlogi Georgiev Boulevard, runs through the neighbourhood Poduyane, and finally flows into the Iskar River. The well known Orlov Most is build over this river.