Toledo was walled by Romans, and a lot of its stones were reused later in built walls, as the original perimeter was subsequently tripled. The Visigothic King Wamba renewed the Roman fortifications, sculpting in its gates an inscriptions. The inscriptions were destroyed by the Muslims, and restored in 1575 by the Corregidor Juan Gutiérrez Tello.
The Arabs widened the city and the walls. After the Reconquista, the walls were again advanced in outer line and new gates were constructed. The gates and towers of the Walls of Toledo have survived until these days.References:
The city walls of Avila were built in the 11th century to protect the citizens from the Moors. They have been well maintained throughout the centuries and are now a major tourist attraction as well as a UNESCO World Heritage Site. Visitors can walk around about half of the length of the walls.
The layout of the city is an even quadrilateral with a perimeter of 2,516 m. Its walls, which consist in part of stones already used in earlier constructions, have an average thickness of 3 m. Access to the city is afforded by nine gates of different periods; twin 20 m high towers, linked by a semi-circular arch, flank the oldest ones, Puerta de San Vicente and Puerta del Alcázar.