The Skopje Fortress, known locally as Kale, sits on a rocky hill above the Old Bazaar and the Vardar River. The walls visible today are primarily Ottoman — 11th and 12th century — built on top of Byzantine and earlier foundations. The site has been fortified since at least the 6th century, when the Byzantine Emperor Justinian built a major stronghold here. It guarded the crossing of the Vardar and the main road through the Balkans.
Today the fortress walls are freely walkable and offer the best panoramic views over the city: the river below, the minarets of the bazaar, the neo-baroque explosion of the new centre, and the mountains rising behind. The interior of the fortress contains an excavation area and occasional open-air exhibitions. Entry is free. The walk up from the bazaar is short and steep.