Rome, October 17 - Rome Mayor Virginia Raggi on Wednesday called for sponsors to fund the upkeep and repair of the city's ancient Aurelian Walls, parts of which have crumbled in recent years. She called the walls "an extremely important part of the city, covering a lot of ground and delicate where projects are concerned". The Aurelian Walls are a line of city walls built between 271 AD and 275 AD in Rome, Italy, during the reign of the Roman Emperors Aurelian and Probus. They superseded the earlier Servian Wall built during the 4th century BC. The walls enclosed all the seven hills of Rome plus the Campus Martius and, on the left bank of the Tiber, the Trastevere district.