Nestled in the historic center of Coyoacán is an unusual library devoted to the preservation not of literature, but of sound. Housed in the historic Casa Alvarado, Mexico's National Sound Library contains a singular record of the country's music, recordings, and even the voices of its most famous residents.

Built in the 18th century under Andalusian and Moorish influence, Casa Alvarado has hosted many institutions, including the Ministry of Finance and Public Credit, the headquarters of the Encyclopedia of Mexico, and an office of the Octavio Paz Foundation. But its current resident is also one of its most remarkable, holding a comprehensive archive of the country's most important audiovisual records. 

The first two floors of the building are devoted to conservation and the third to cataloging and digitizing. Elsewhere in the museum, group listening rooms allow anyone to access any sound file held in the museum. And for library purists, there are also books—over 2,000—concentrating on music, the history of sound, and the culture of listening. You can also request to hear the voices of Mexico's famous historical figures; the most-requested are Frida Kahlo's and Mexican Independence Hero Miguel Hidalgo y Costilla's.

The building itself is beautiful, with a main gate carved in wood inspired by the main doors of the Old College of San Ildefonso. And the recently restored gardens contain ornamental trees from Coyoacán's traditional vegetation, some half a century old. Installed within the flora is a multichannel sound system that plays works of sound art, experimental composition, and other music within the library's archives.