Urnlos

Urnlos is a fictional planet that appears in speculative fiction and role-playing games. It is presented as a world of varied biomes, including mist-covered highlands and extensive subterranean networks formed by limestone karst. The planet is noted for abundant mineral deposits and bioluminescent life in caves.

The name Urnlos is said to derive from an extinct language known as Urni, where elements meaning "stone" and "silence" or "hush" are combined. In-universe glossaries often treat the term as a toponym rather than a descriptor, and different works use it with slightly varying connotations.

Urnlos features a temperate climate overall, with heavy seasonal rainfall fueling dense forests in uplands and broad river plains. The most striking feature is a vast karst region of caves and underground rivers that hosts unique ecosystems and supports human settlement. The interwoven surface and subterranean environments give rise to distinctive modes of travel, trade, and shelter.

The planet’s intelligent inhabitants are the Urnari, a humanoid people adapted to both cave and surface life. They are skilled builders, renowned for stonework and mineral-based luminescence used in art and architecture. Social structures range from clan-based groups in the highlands to city-states within cavern complexes, and practice a tradition of mapping and surveying underground networks.

Historically, the Urnari speak of long-vanished ancestors known as the Ancients, credited with constructing large cavern-temple ruins. Modern exploration centers on those ruins, with archaeologists and prospectors uncovering inscriptions and mineral artifacts. The ruins influence Urnari identity and intergroup diplomacy, and merchants trade mineral goods with off-world visitors.