Duomo di San Martino

This guide to the Duomo di San Martino in Lucca starts with a puzzle hiding in plain sight: one of the cathedral's three entrance arches is noticeably narrower than the other two. It traces that oddity back to a bell tower the thirteenth-century masons refused to tear down, and follows the same stubbornness up into the loggias above, where no two columns match, twisted, fluted, carved with animals chewing on foliage. Local memory ties it to a sculpting competition Lucca once held for its finest column, one the judges could never settle. Look for the labyrinth pattern cut into the smallest arch's stone while you take it in.