Buenos Aires is based on a square, rectangular grid pattern, save for natural barriers or the relatively rare developments explicitly designed otherwise (most notably, the Parque Chas neighborhood). The rectangular grid provides for -long square blocks named ''manzanas'' . Pedestrian zones in the central business district such as Florida Street are partially car-free and always bustling, access provided by bus and the Underground (subte) Line C. Buenos Aires, for the most part, is a very walkable city and the majority of residents in Buenos Aires use public transport.