Barcelona. Towering temple columns, ancient city walls, and subterranean stone corridors provide a window into Roman-era Barcino.  Take a stroll through the shadowy lanes of the Gothic quarter, past tranquil plazas and soaring 14th-century cathedrals. In other parts of town bloom the sculptural masterpieces of Modernisme, a mix of ingenious and whimsical creations by Gaudí and his Catalan architectural contemporaries.