The Zarzuela Hippodrome is one of the most exceptional works of Spanish architecture of the first third of the 20th century, and the grandstand structure, with its marquees, among the century’s great works (in 2009 it was declared a cultural interest site in the monuments category). The building’s history has been eventful and this has had a bearing on its restoration. Arniches, Domínguez and Torroja won the competition for the new hippodrome in 1934, but two years later, the concrete structure practically completed, construction was interrupted by the Spanish Civil War. The war ended in 1939 and with the architects in exile, all documents of the project (except those involving the structures) disappeared. Even so, the building was inaugurated in 1941 with minimal installations that would be improved over time until it was closed in 1997, a few years before the competition for restoration was called.

With the documentation missing, ‘finding’ the original project became the key to refurbishing the building, and this determined the directives of the operation: eliminate additions ; restore the grandstand; adapt to the topography and separate areas for horses from zones where people circulate, in accordance with the 1934 plans; and to allow for future enlargements underground so as not to interfere with views of the historic buildings...