Slicing across the regular blocks of Barcelona at an angle, the Avinguda Diagonal is one of the city's most important thoroughfares, running for several kilometres from the inland districts down towards the sea. Its name comes directly from the way it cuts diagonally through the grid. The avenue was part of the celebrated 19th-century expansion plan for the city drawn up by the engineer Ildefons Cerda, whose design extended Barcelona beyond its old walls in a vast, even grid crossed by a few broad diagonal arteries. Along its length the character changes from district to district, passing grand Modernista mansions and the shopping streets of the upper Eixample, through business and university quarters, to newer commercial and residential developments closer to the waterfront. Among the notable buildings on or near the avenue are works of the city's great architects, including Modernista houses such as the Casa de les Punxes, and later landmarks reflecting Barcelona's 20th- and 21st-century growth. The Diagonal has long carried major traffic, trams and metro lines, and successive city administrations have reshaped parts of it, widening pavements, adding cycle lanes and extending the tram network as part of efforts to balance cars with other transport. It also serves as a route for large public events and demonstrations, its width and length making it a natural setting for parades and gatherings. At its lower end the avenue reaches the Diagonal Mar area and the sea, developed for the 2004 cultural forum, while inland it climbs towards the foot of the Collserola hills. As both a working transport corridor and an address for offices, shops and homes, the Diagonal is woven through daily life in the city in a way few single streets are. The Metro and tram lines that run beneath and along it make the avenue one of the busiest public-transport corridors in the city.

Type: Tourist Attraction

Address: Avinguda Diagonal, Barcelona, Spain