The library was opened on 28 February 2011. It is in the heart of Madrid of the Austrias and occupies the site of a former mansion belonging to one of the oldest lineages in  Madrid: the Vargas, whereby Iván de Vargas was the master of the patron of the city, San Isidro Labrador.

It has a surface area of  2,884 m2 divided into four floors. Its architecture considers an intense dialogue between history and modernity. The façade on Calle Doctor Letamendi stands out for its traditional compositional language, in contrast to the area of the building on Calle San Justo, made up of a large cubic volume, which responds to today’s architectural standards. Made out of granite, with a large opening, whereby its design is broken to create a gap that reveals a large  magnolia and the iroko wood  enclosures of the library spaces.

It boasts various spaces: consultation and reading room, periodicals, a section for children and teenagers, an Internet consultation area and a multi-purpose room. Due to its historic roots in the city, it also has a reading room specialised in documentary archives on Madrid. Inside, two centenary magnolia trees stand out, along with the well parapet with a carved medieval  image of San Isidro. 

In front of the main entrance stands The Reader, a sculpture by Félix Hernando, as an invitation to use the library.