It takes its source from the Bosna Ridge in the Strandzha Mountains, running for 48.5 km to empty into the Black Sea near Cape Saint Demetrius between Dyuni and Primorsko.

The lower Ropotamo is a popular tourist attraction because of the water lilies and the rock formations above the river, on some of which white-tailed eagles nest.

The Ropotamo then forms a narrow gorge between the ridges Medni Rid and Uzun Bair and enters a wide marshy valley near its mouth.

It borders the basins of the rivers Izvorska that empties into Lake Mandrensko to the north-west, Veleka to the south-west and Dyavolska reka to the south and south-east.

The lower course hosts abundant populations of European white water lily (Nymphaea alba) and a number of rare plant and animal species.