The one going straight to the basilica is Gaudí Avenue, named after Antoni Gaudí, the architect who designed the Sagrada Família (as well as other landmarks like Park Güell, Casa Milà / La Pedrera, or Casa Batlló); it was designed to connect the two landmarks of the Sagrada Família and the former Hospital de la Santa Creu i Sant Pau (today a UNESCO world heritage site).

The one in the background is Diagonal Avenue (no, really), one of the main thoroughfares in the city, intended by Ildefons Cerdà (designer of the Eixample) to cut through his grid layout together with Meridiana Avenue (which roughly follows the Paris meridian, or rather the Barcelona-Dunkerke one; there's also the perpendicular Paral·lel Avenue, of course, though sadly they don't cross), crossing at the Plaça de les Glòries Catalanes, which Cerdà intended to become the new city centre (alas, the Plaça Catalunya, some 17 blocks to the south, ended up taking that role).