When an unremarkable 1950s municipal building on this site was demolished in 2010, the construction crew made an exciting subterranean discovery: a Byzantine cistern dating from the reign of Emperor Theodosius. Research has found that the structure was built between 428 and 443 and was known as the Constantinus or Theodosius Cistern. Now restored, a wooden walkway allows visitors to easily admire the water-covered marble base, vaulted brick ceiling and 32 massive marble columns (unfortunately marred with modern metal braces).
One of the Roman city's three major cisterns (with the 4th century Binbirdirek Cistern and the 6th century Basilica Cistern), the structure stored water brought to the city from the Belgrade Forest by the Aqueduct of Valens.
Admission to the cistern was free at the time of research, but a fee may be introduced in the future.