San Martín Pinario Monastery and Church, from the late 16C, make up Santiago de Compostela's second largest monument after the cathedral; the monastery alone occupies 20 000m2! Giving onto Plaza de la Inmaculada, it has a colossal façade with sturdy Doric columns. With its immense single nave and its retable, the interior of the church, the work of the great architect Casas y Novoa, is striking.