San Andrés church was built in the quarter of Ajates (a suburb of mediaeval origin in which the main trade was masonry) in the second quarter of the 12th century. It was made in Caleno granite (very typical of the Romanesque style in the town) and is set according to liturgical criteria with an upper end with three apses that correspond to the three naves in the interior; it does not have a transept nave. The protruding central apse is of particular interest thanks to the number of figures and capitals and the closed arches on the straight section of the upper end, which stand as a unique example of Romanesque capitals. The variety of icons on the interior and exterior capitals is the largest of all of Ávila's Romanesque buildings and is associated with the Masters of León. The central apse has two absidioles of a smaller size and a plainer composition.
The upper end is covered with decreasing stepped vaults: barrel vaults along the straight section and calotte vaults along the curved section. The southern absidiole has a lobulated arch used as the entrance and unparalleled in any other church in Ávila at the time.
The south front has a semi-circular window and the keystone of the semi-circular archivolt contains a Chi Rho which, fitted in the 13th century, is considered as the first of its kind in the town. The tower stands next to the western side, built onto the nave during or after the 14th century.
References:Saint-Georges de Boscherville Abbey is a former Benedictine abbey. It was founded in about 1113 by Guillaume de Tancarville on the site of an earlier establishment of secular canons and settled by monks from the Abbey of Saint-Evroul. The abbey church made of Caumont stone was erected from 1113 to 1140. The Norman builders aimed to have very well-lit naves and they did this by means of tall, large windows, initially made possible by a wooden ceiling, which prevented uplift, although this was replaced by a Gothic vault in the 13th century. The chapter room was built after the abbey church and dates from the last quarter of the 12th century.
The arrival of the Maurist monks in 1659, after the disasters of the Wars of Religion, helped to get the abbey back on a firmer spiritual, architectural and economic footing. They erected a large monastic building one wing of which fitted tightly around the chapter house (which was otherwise left as it was).