The church of San Ginés is one of the oldest churches in Madrid. It was one of the churches of the medieval Madrid, of Mozarab origin, from between the 12th and 13th centuries, and its name comes from the fact that it was dedicated to the patron saint of notaries and secretaries, Saint Genesius of Arles (San Ginés de Arlés). it was rebuilt in 1645.
The church is preceded by an atrium enclosed by railings. It has a Latin cross plan, with a nave and two aisles separated by semicircular arches and several side chapels and the altarpieces belong to the Neoclassical-Romantic school. It was, however, totally reconstructed after suffering several fires, so few remnants of the original church, such as the bell-tower, remain. In 1870, the loggia and atrium facing the Calle Arenal were added.
One of the most curious items on display is a stuffed crocodile, which is said to have been brought over from the Americas during the reign of the Catholic Monarchs.
References:The Basilica of Santa Maria in Trastevere is one of the oldest churches of Rome. The basic floor plan and wall structure of the church date back to the 340s, and much of the structure to 1140-43. The first sanctuary was built in 221 and 227 by Pope Callixtus I and later completed by Pope Julius I.
The inscription on the episcopal throne states that this is the first church in Rome dedicated to Mary, mother of Jesus, although some claim that privilege belongs to the Basilica di Santa Maria Maggiore. A Christian house-church was founded here about 220 by Pope Saint Callixtus I (217-222) on the site of the Taberna meritoria, a refuge for retired soldiers. The area was made available for Christian use by Emperor Alexander Severus when he settled a dispute between the Christians and tavern-keepers.
The church underwent two restorations in the fifth and eighth centuries and in 1140-43 it was re-erected on its old foundations under Pope Innocent II.