Between the 11th and 13th centuries, Romanesque art developed with a style similar to Roman art. Romanesque architecture featured stone churches built in a Latin cross layout with a nave, transept, and apse. Barrel vaults and thick walls supported heavy stone roofs, while buttresses reinforced the walls. Inside, the churches had few windows, making it dark, and paintings and sculptures served to educate the largely illiterate population. Romanesque paintings used frescoes directly on walls, while sculptures often decorated capitals and altars.