Kurl

Kurl is the name of a planet not far from Federation spae which was home to the extinct Kurlan civilization. The remains of the colony site resulted in many archaelogical expeditions conducted to uncover the past of planet's long dead inhabitants.

The planet was actually an ancient Trill colony where genetic experiments were conducted on the Symbionts which resulted in the creation of the Parasite species. (DS9 novel: Trill: Unjoined).

The archaeologist Richard Galen made numerous findings on the planet and uncovered a Kurlan naiskos. (TNG episode: The Chase)