Salamanca
This sunny sandstone city boasts Spain's grandest plaza, its oldest university, and a fascinating history, all swaddled in a strolling, college-town ambience. A youthful and less touristy version of Toledo, Salamanca is home to a series of monuments, a pair of buttress-sharing cathedrals from different centuries, clusters of cloisters, and some surprisingly good museums. Join the paseo with the local crowd through Plaza Mayor, down Calle de Rúa Mayor, and out to the river. The young people congregate until late in the night, chanting and cheering, talking and singing. When I asked a local woman why young men all alone on Plaza Mayor suddenly break into song, she said, "Doesn't it happen where you live?"