The old walled city of Tripoli, the Medina, is one of the classical sites of the Mediterranean. The basic street plan was laid down in the Roman period when the walls were constructed on the landward sides against attacks from the interior of Tripolitania. The high walls survived many invasions, each conqueror restoring the damage done. In the 8th century the Muslim ruler built a wall on the sea-facing side of the city. Three great gates gave access to the town, Bab Zanata on the west, Bab Hawara on the south east and Bab Al-Bahr in the north wall.