Ávila was founded as the Roman town of Avela. The wall, which completely encloses the city, was built in the late 11th century as a defense against attack by the Moors, with some modifications in the 14th century. This city wall is the best preserved in Spain, and is about 40 ft high, 10 ft thick, and about 8000 ft in circumference. The wall has 90 towers, and eight gates for entry to and exit from the city. The walls and gates were built using some stones from Roman buildings.