Besieged by Hannibal, then ruled by Rome, Salamanca was defined, in the early 13th century, by the founding of its great university. It’s now a Unesco World Heritage site and its intricately carved golden sandstone churches, palaces and plazas blaze in the sun high above the river Tormes. At night, they are magically floodlit, and the city bubbles, Spanish style, with life.