The only preserved portion of the medieval forts of Zemun are the remains of its Citadel. This was a four-angled castle with a circular tower on each side, as determined from the ruins of the external walls and towers, reaching up to 2 meters high. The intermediate directions were used in the orientation of the castle. The walls were made of broken stone, coated with bricks and lime mortar. It was first mentioned as early as in the 9th century, but more often after the 12th century. In 1609, the castle was still standing; however, it has been in ruins since the 18th century.
The Old Core of Zemun is an urban matrix which developed in the 18th and 19th century under special historical conditions and in a specific geopolitical position. The settlement mentioned as Zemlen in the 12th century was made on the foundations of the Roman Taurunum. Maintaining its continuity until the 18th century, it grew into an urban settlement of an irregular rectangular shape, with a network of mainly orthogonal streets. Material evidence of its 200-year development have been kept in the existing street grid, buildings and the long-term continuity of its urban, military, sanitary, educational and religious institutions, commodity stores and artisan shops. The preserved building material documents the development of construction techniques and the diversity of architectural shapes, styles and cultural influences. The Old Core of Zemun has 59 streets, six squares and more than 900 buildings, the oldest of which include the White Bear Pub (BeliMedved), Nikolajevska Church, Karamata House etc. Some of the buildings belonging to this whole have been subjected to conservation and restoration treatments
Gardoš Tower, Belgrade, Serbia