Calumdarian was a volcanic rocky world located in the Expansion Region. Its atmosphere was breathable for a short time period, but was filled with smoke that made long-term exposure difficult. The Alliance to Restore the Republic operated a secret on Calumdarian. Shortly after the Cyrkon Extraction, Luke Skywalker and several Rebel pilots located Han Solo and Chewbacca on Balnab, requesting that the smugglers transport several crates of cargo to the outpost in the Millennium Falcon.