Remains of the Insula dell'Ara Coeli in Rome. Insulae formed part of extensive city planning in imperial Rome, being the equivalent to apartment blocks or condominiums built for housing the urban poor. They accommodated 350 or so residents. The insula Ara Coeli is at the foot of the Capitoline Hill and dates to the first two decades of the second century AD. Constructed of brick-faced concrete, it was formerly on five storeys of which four remain and consisted of single shop units (tabernae) on the first three storeys and apartments above. In the 11th century the upper floors became part of the church of San Biagio de Mercato. The Church of Saint Rita was built on top of that church: where the Romanesque belfry is evident. When the church of Saint Rita of Cascia was dismantled in the 1930's the original Roman building was revealed.