The Eixample is characterised by long straight streets, a strict grid pattern crossed by wide avenues, and square blocks with chamfered corners This was a visionary, pioneering design by Ildefons Cerdà, who considered traffic and transport along with sunlight and ventilation in coming up with his characteristic octagonal blocks, where the streets broaden at every intersection making for greater visibility, better ventilation and (today) some short-stay parking space. The important needs of the inhabitants were incorporated into his plan, which called for markets, schools, hospitals every so many blocks. Today, most of the markets remain open in the spots they have been from the beginning.
Some parts of the Eixample were influenced by Modernista architects, chief among whom was Antoni Gaudí. His work in the Eixample includes the Casa Milà (nicknamed La Pedrera) and the Casa Batlló, both of which are on the wide Passeig de Gràcia, as well as the Sagrada Família. Other architects who made highly significant, and certainly more numerous, contributions to giving the Eixample its characteristic appearance include Josep Puig i Cadafalch, Josep Domènech i Estapà, Josep Vilaseca i Casanovas and perhaps above all Enric Sagnier i Villavecchia, responsible for a total of over 500 buildings in the city (not all of them in the Eixample).