Naples

The Blade of Spaccanapoli

Naples hides three cities stacked on top of one another — Greek, Roman and Baroque — and you'll literally walk over all three along Spaccanapoli, the straight street that has cut the historic centre in half for 2,500 years. You'll hunt for a rose window with no glass, count marble angels above an ancient Greek agora, and decode a facade nobody has ever fully read, while underground Naples keeps beating beneath your feet. It's a little under 2 km, mostly flat.