The most internationally known guest is the Argentine writer and poet Jorge Luis Borges, who between 1919 and 1921, staying at what was then called the Pensión Americana, wrote his first ultraist poems.
You can see a commemorative plaque on the exterior of the building.
Borges’s room is number 416, on the fourth floor, on the corner with 3 balconies overlooking Tetuán and Carmen streets.