Also known as Porta Zamboni, this 13th-century gate was the main entrance to Bologna's University Quarter from Ferrara, and originally had a drawbridge and house for guards. Its location at the intersection of the city's main ring road and Via San Donato has long made it a target of road engineers, but it has survived with its tower and was recently restored. It's also the terminus for several bus lines into the hinterland.
Piazza Porta San Donato
Image by Threecharlie, Creative Commons License