Burgas archaeologists have uncovered a monumental building in the medieval town of Rusokastro in the final days of this year's dig.

The building stands next to the inner south wall of the fortress, in the town's central district. It is 7.60 metres wide. Its length is not yet known.

The walls are 1.1 metres thick and built of stones set in a lot of mortar. Inside, they are covered with a thick layer of pink waterproof mortar, so the archaeologists think the building was probably a water tank or a food store.

They believe the part uncovered is most likely the ground floor, and say there may have been a second, residential floor above it.

The team also found many smaller items, including silver coins of Tsar Ivan Alexander, Venetian silver groats called matapans, copper coins and other objects.

All the finds are now in the restoration workshop of Burgas museum, where they are being cleaned.