[citation needed] The building encloses a large central patio with ranges of two storeys, the windows set in slightly sunken panels between flat pilasters.

[2]: 128 On 12 March 1784, Juan Bautista Muñoz, a historian who was attempting to write a history of the New World, wrote to José de Gálvez, the Minister of the Indies, suggesting the idea of creating a centralized archive for documents relating to the Americas.

José de Gálvez had already been considering the idea for a decade and wrote back on 24 April, encouraging him to look in Seville and Cadiz for potential buildings that could house the archive.

He wrote to Gálvez on 8 June, enthusiastic about selecting this structure since it was a solidly built made entirely of stone and contained sufficient space for a large number of documents.

[2]: 129–130 Gálvez communicated the idea to monarch Charles III, who on 27 June 1784 issued a letter instructing Muñoz to draft a proposal for the work needed to convert the building into the Archive of the Indies.

[2]: viii  The project was to bring together under a single roof all the documentation regarding the overseas empire, which until that time had been held among various repositories, including in Simancas, Cádiz and Seville.

Here are Miguel de Cervantes' request for an official post, the Bull of Demarcation Inter caetera of Pope Alexander VI in which he divided the world between Spain and Portugal, the journal of Christopher Columbus, maps and plans of Spanish American cities, in addition to the ordinary records that reveal the month-to-month workings of the whole vast bureaucatic machinery of the empire.

Today, the Archive of the Indies houses some nine kilometers of shelving, in 43,000 volumes and some 80 million pages, which were produced by the administrators in the Americas and the Philippines: The structure underwent a thorough restoration in 2002–2004, without interrupting its function as a research library.