Tvrdina Kale Fortress
Dominating the skyline of Skopje, this Game of Thrones–worthy, 6th-century AD Byzantine (and later, Ottoman) fortress is an easy walk up from the Čaršija and its ramparts offer great views over the city and river.
Inside the ruins, two mini museums were being built at the time of writing to house various archaeological finds from Neolithic to Ottoman times. This will be a welcome addition to the site, as there are no information boards at the fortress at present.