The grandest of Turin's seventeenth-century arcaded streets, running for a full kilometre from Piazza Castello down to the river. The porticoes are deep enough to be a building in their own right; you can walk the entire length in the rain without getting wet, and on a hot day you stay in the shade.
The Savoys had a private corridor built into the upper floors so the royal family could move from the Royal Palace to their riverside park without ever stepping outdoors. Below the arcades today are the city's best second-hand book shops, antiquarian dealers, and a couple of historic cafes — Fiorio and Mulassano are both close by.