Four doors, of which the door of Sant Roc, that used to be an access to the fortified city of Mahon. Among those four doors, Sant Roc is the only one still existing nowadays.
The door of Sant Roc is also one of the rare vestiges of the medieval murals of Mahon. The latter were built on the Arab walls by order of King Alfonso III, at the end of the 8th century, to defend the city against enemy attacks. Only the seafront wasn't fortified as the cliffs form by themselves a natural defence.