Vasari Corridor

The Vasari Corridor is an elevated enclosed passageway in Florence, central Italy, connecting the Palazzo Vecchio with the Palazzo Pitti. Beginning on the south side of the Palazzo Vecchio, it joins the Uffizi Gallery and leaves on its south side, crossing the Lungarno dei Archibusieri, then following the north bank of the River Arno until it crosses the river at Ponte Vecchio. At the time of construction, the corridor had to be built around the Torre dei Mannelli, using brackets, because the tower's owners refused to alter it. The corridor conceals part of the façade of the Church of Santa Felicità. It then snakes its way over rows of houses in the Oltrarno district, becoming narrower, to finally join the Palazzo Pitti. The corridor's full length is approximately one kilometre.

Wikipedia