Rusokastrenska reka
General data
- Name: Rusokastrenska reka
- Water system: Lake Mandrensko
- Water type: River
- Progression: Lake Mandrensko -> Black sea -> Mediterranean Sea -> Atlantic Ocean -> Planet Earth
- Climates: Subtropical, Temperate
- Continents: Europe, Asia
- Countries: Bulgaria
The Rusokastrenska reka is a 65 km long river in eastern Bulgaria. In 1332 near the river's left banks close to the fortress of Rusokastro the Bulgarian emperor Ivan Alexander defeated the Byzantine army under emperor Andronikos III Palaiologos in the battle of Rusokastro.
The river takes its source from a spring on the southern slopes of the Hisar Heights at an altitude of 335 m, some 2.4 km southeast of the town of Karnobat. It flows in southeastern direction through the Burgas Plain in a wide valley covered with farmlands. At the village of Zhelyazovo it bends north to bypass the isolated height of Rusen Kamal (108 m), takes its largest tributary the Hadzhilarska reka, and continues southeast. The Rusokastrenska reka flows into Lake Mandrensko near the village of Konstantinovo. The lake itself drains into the Gulf of Burgas in the Black Sea.
Its drainage basin covers a territory of 525 km2.
