"The practical success of a theoretical project": this is how architect and urban planner Manuel de Solà-Morales defined Ildefons Cerdà's Eixample. Now this statement can be read within Models. Cities and utopias 1859-1958, the exhibition that the COAC is hosting until October 18th as part of the Ildefons Cerdà Year. "A lot was already said about Cerdà during the Cerdà Year in 2009. What we had left in the inkwell was to place him alongside Le Corbusier, Frank Lloyd Wright, the greats," states Fernando Marzá, the curator of the exhibition, together with UPC urban planner Carles Crosas and Generalitat architect Beth Tuà. "Cerdà did not just plan a city; he wrote a treatise on urban planning, almost the first one," Marzá asserts. Before drawing the Eixample, Cerdà created a great topographical map and a statistical study of how the working class lived. "Engels had done it in London five years earlier," the curator recalls.