Translation:The corners are round, not square!
In Craiova there is a place called La Rotunda... it's a building that used to be a market, and the shape of the building is round. Today it's a bank, but that's beside the point. It's the only building in town that's round, so you can tell the Taxi driver "La Rotunda" and they know to drop you at the corner near that building, or maybe at the taxi stand across the street.
There are no corners on La Rotunda.
For a street corner to be round -- sometimes there is a slight roundedness to the sidewalk at a street corner. Maybe that's what they mean?