Barcelona has the Mediterrenean sea at her feet, and Collserola Mountains protecting her back. On the sides, rivers Llobregat on the South and river Besos on the north, finish to round an almost perfect geographical spot.
The city has a surface of 100squarekm, with a population of 1.621.537 inhabitants. They are organized in ten districts – Ciutat Vella, Eixample, Sant–Montjuic, Les Corts, Sarrià–Sant Gervasi, Gràcia, Horta–Guinardó, Nou Barris, Sant Andreu I Sant Martí – which in total complete the 72 "Barrios" (neighborhoods or as we call them, Planets).
The division has an historical explanation, Ciutat Vella was the origin of Barcelona, the centre, and Eixample was the area where the city expanded after the walls were thrown down. The rest of the districts were added naturally in the process.
WalkingPlanets! Concentrates in Ciutat Vella district, 5km of surface where Raval, Gotic, Barceloneta and Born LOCAL people mingle.