Chief Sepass Theatre Part of the Langley Fine Arts School, the Chief Sepass Theatre is a 320-seat facility located in historic Fort Langley. The multi-purpose venue, complete with sound, light and projection systems is available for musicals, plays and other stage productions. Address: 9096 Trattle St. Fort Langley BC CAN V1M 2S6 Send an Email 1 604 888-3113