Thelasa-vei Province is a southern province of the planet Andor, found on the Southern Archipelago. The region is reknowned for its festivals and celebrations, including the Spring Water Festival.
Thelasa-vei is home to the clans Cheen and Thitar who reside within Cheen-Thitar Keep. (DS9 - Worlds of Star Trek: Deep Space Nine novel: Andor: Paradigm)