On a low ridge above the old part of town, the remains of a medieval fortress survive in fragmentary but evocative form. The walls and towers are largely collapsed, reduced to foundation courses and scattered stonework, but the hilltop position makes the site worth visiting for the views over the valley and the sense of the town's long history.
The fortress dates from at least the Ottoman period — the 17th-century traveller Evliya Çelebi recorded Radoviš as a substantial settlement with 3,000 to 4,000 inhabitants at that time — and may overlie earlier Byzantine or Serbian medieval structures. The hill is easily walked from the old quarter. There are no facilities or interpretation panels; it is the kind of ruin you discover rather than visit, which is part of its appeal.