San Gregorio is a former church founded in the 9th century and, in the 13th century, it became a Benedictine abbey. In the mid-15th century it was rebuilt to the current appearance under design by Antonio da Cremona. In 1775, after a long period of crisis, the monastery was closed and in 1807, after the Napoleonic occupation of Italy, also the parish church was suppressed. Deconsecrated, it was converted in a mint laboratory and then an art restoration center. It is now closed and not used.
It has a Gothic exterior with an ogival portal, elongated mullioned windows with ogival top, and apse.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.