The island of Lokrum is a 10-minute ferry ride from Dubrovnik harbour, and uninhabited except for a dozen or so peacocks. Lokrum is covered in pine woods and shaded footpaths, and by climbing to the highest point at 91 metres you will find this ancient Napoleonic fortress built in 1806.
From here there are superb views of Dubrovnik City and the surrounding coastline with the village of Cavtat in the far distance.