Shishmans Nikopol fortress or castle is located on a hill near the western end of Nikopol. It was heavily fortified stronghold and was of major strategic importance to the well-protected harbor. As of today the castle is preserved in relatively good condition, Shishmans door that dates back to the early 19th century .. During archaeological excavations have found buildings of the Second Bulgarian Kingdom and parts of the fortress wall. According to chroniclers King Shishman, who moved into the castle, had a stronger, better fortress of Nikopol. Fortress is unfortunately closed to visitors.