Barcelona is the capital and largest city of Catalonia, located along Spain's northeastern coast. Some of its most important landmarks and neighborhoods include La Rambla, a popular tree-lined pedestrian street; the Gothic Quarter, home to the large Cathedral; Plaça de Catalunya, the central square where the old city meets the modern Eixample district; and Passeig de Gràcia, a major avenue known for shopping and architecture. The document provides brief descriptions of these areas of interest in Barcelona.