The Byzantine castle on the Panagia promontory dominates the old city from above. Originally built in the 5th or 6th century to defend the port of Neapolis — as Kavala was then known — it was substantially expanded during Byzantine and Ottoman times. The walls enclose the old residential quarter and provide the best panoramic view of the city, the bay, and the island of Thassos on the horizon.
The castle is entered through a gate at the northern end of the Panagia district. The interior walls, towers, and cisterns are well preserved. A small open-air theatre inside the enceinte is used for summer performances. The views from the battlements — over the harbour, across the bay, and back over the tiled rooftops of the old quarter — are the best in Kavala. The walk up from the lower town through Panagia's lanes is itself worth doing; the castle is the destination that makes it purposeful.