Toledo, Spain

Historic center Toledo packs three religious traditions into one hilltop. Known as the City of Three Cultures for the centuries when Christians, Muslims and Jews lived side by side, it keeps synagogues, a former mosque and a towering Gothic cathedral within a few minutes' walk of each other, all inside the town wall and the deep bend of the Tagus river. The center joined UNESCO's list in 1986. The lanes are steep, narrow and confusing, which is the point: put the map away for an hour. Toledo is a classic day trip from Madrid, so the main streets are busiest from late morning to late afternoon, and a night inside the walls is the way to see it calm.