Church in Bologna

A hilltop sanctuary reached by the longest covered walkway in the world — nearly four kilometres of portico and six hundred arches, climbing steadily out of the city. The walk is the attraction and takes about an hour up. Views over the Apennines at the top. Buses exist for the way down.

Not one church but a linked complex of several, built and rebuilt from late antiquity onward around a courtyard — locally called the seven churches, though the count has changed over the centuries. Free, quiet, and the most atmospheric half hour in the city. On a sloping square with cafés along one side.

Enormous, and famously unfinished — the marble facing stops halfway up the front and simply becomes brick. Inside is a meridian line laid into the floor in 1655, still accurate, with a hole in the roof that puts a disc of sun on it at noon. Free, and a much stranger building than it first appears.