The area covered by Singidunum spreads over the territory of 5 modern municipalities of Belgrade. Castrum occupied part of today's Belgrade Fortress. Civilian zone spread from the Kralja Petra Street, over the both Sava and Danube slopes, till Kosančićev Venac, extending in a series of necropolises from Republic Square, along the Bulevar kralja Aleksandra all the way to the Mali Mokri Lug. Necropolis at Republic Square contained a well-shaped graves from the 1st century AD. In general, the largest section of the civilian settlement was situated between the modern Simina and Brankova streets, and the Republic Square. As for the Fortress itself, the rectangular castrum covered what is today the Upper Town of the Fortress and the Kalemegdan Park. The castrum had tall walls, built from the white Tašmajdan limestone and spread over the area of to , being shaped as an irregular rectangle (approximately ).