In Jorge Luis Borges’s story “Tlön, Uqbar, Orbis Tertius,” the fictional country is Uqbar. The narrator first encounters it through a supposedly encyclopedic entry that may exist only in a strange or fabricated version of a reference book.
Uqbar is presented as an obscure land with unusual religious history, geography, and literature. Its stories do not describe ordinary reality but instead refer to the imaginary regions of Mlejnas and Tlön. As the narrative unfolds, the boundary between invention and reality becomes increasingly unstable.
Tlön is not the country asked for: it is a fictional world created through an immense intellectual project. Orbis Tertius is the secret organization associated with that project. This layered naming is the source of a frequent quiz mistake, because all three terms appear together in the title.
Borges first published the story in the Argentine journal Sur in May 1940. It later became part of Ficciones, his influential 1944 collection, and helped define his blend of philosophical speculation, metafiction, and detective-like investigation.