Cattedrale di San Zeno in Pistoia

You're standing on the Piazza del Duomo, right in the heart of Pistoia, in front of the city's cathedral. Its official name is the Cathedral of Saint Zeno, after Zeno of Verona, and it's the seat of the Bishop of Pistoia. Start with the façade. It's Romanesque, with the same stripes and arches you'll spot on other churches in town, like San Bartolomeo and San Jacopo. Along the bottom runs a portico, and above it are three tiers of little open galleries. That part was added between 1379 and 1440.