The Cathedral of Santa Maria Maggiore stands at the heart of the old town and is most famous for the magnificent portico that precedes its entrance. The cathedral itself was largely rebuilt in the 12th century over an earlier structure, but it is the portico — completed in 1210 and bearing the signed inscription of the Cosmati craftsmen who made it — that draws visitors from across Lazio. The columns are wrapped in spiralling bands of Cosmati mosaic: intricate geometric patterns of coloured stone and glass tesserae, combining red porphyry, green serpentine, and gilded glass in combinations that have not faded in eight centuries. The overall effect, particularly in morning light, is extraordinary.
Inside, the cathedral retains a crypt with early medieval capitals and some fragments of older decoration. The interior was reworked in later centuries and lacks the drama of the portico, but it is worth entering for the crypt and for the atmosphere of a building that has been in continuous use since before the Normans arrived in Italy. The piazza in front is small and quiet, a good place to sit and look at the portico without a crowd in the way.