Complex sentence: It takes its source from the Vitosha Mountain in Bulgaria, runs first westward, then southward, enters Greek territory at the Kula village and flows into the Strymonian Gulf in Aegean Sea, near Amphipolis in the Serres prefecture.
Split into simpler sentences: It takes its source from the Vitosha Mountain in Bulgaria, runs first westward, then southward, enters Greek territory at the Kula village. The river flows into the Strymonian Gulf in Aegean Sea, near Amphipolis in the Serres prefecture.