niches, as at the churches of San Tirso and San Lorenzo, Sahagún Small churches abound across the area, usually having an aisleless nave and projecting apse and a bell turret on one gable. Larger churches often have a wide turret extending across the upper facade with a gallery of openings holding bells, as at Jaca Cathedral Larger monastic churches often have a short transept and three eastern apses, the larger off the nave and a smaller flanking apse off each transept as at La Seu Vella, Lleida. Lateral arcaded porches are a distinctive regional characteristic of small churches. Larger churches sometimes have a similar narthex at the west as at Santa Maria, Ripoll Portals are typically deep set, round topped and with many mouldings, as at La Seu Vella, Lleida, Spain. Portals that are set within porches may be surrounded by rich figurative carvings as at the Cathedral of Santiago de Compostela. Freestanding towers with increasing openings in each stage, like those of Italy, occur with small churches. Small churches are sometimes barrel vaulted and are roofed with stone slabs lying directly on the vault. Wider spaces have timber roofs of low profile, as timber was scarce. Larger churches such as the Cathedral of Santiago de Compostela, have barrel vaults, sometimes with transverse arches marking the bays. Abbey churches of later French foundation have ribbed vaults. Larger monastic churches and cathedrals have nave and aisles and follow French plans, including chevets as at Avila Cathedral. The crossing of a large church sometimes has an octagonal tower or dome supported on squinches, as at Santa Maria, Ripoll and the Cathedral of Santa Maria d'Urgell . At the Old Cathedral, Salamanca and the Cathedral of Zamora there are polygonal crossing domes on pendentives, with narrow windows and with four small corner turrets. Externally, many large churches are fortresslike, such as Lisbon Cathedral and the Old Cathedral of Coimbra in Portugal and the Sigüenza Cathedral, Spain Rose windows with pierced tracery similar to those that occur in Pre-Romanesque churches of Oviedo are a feature in some facades, such as that at the Monastery of Santa María de Armenteira, Galicia. Notable examples The Cathedral of Santiago de Compostela, Santiago de Compostela, Galicia, Spain Santa Maria de Ripoll, Ripoll, Catalonia, Spain The Cathedral of Santa Maria d'Urgell, La Seu d'Urgell, Catalonia, Spain Jaca Cathedral, Jaca, Aragon, Spain The cloister of the Abbey of Santo Domingo