Discovered on stardate 46379.1 by Deep Space Nine science officer Jadzia Dax, the Bajoran Wormhole is the first and only completely stable wormhole known to the Federation, with either end remaining at a fixed point in space.
This "tunnel", approximately 90,000 light years long, connects the Alpha to the Gamma Quadrant with the same time coordinates, providing virtually instantaneous and reciprocal access. The wormhole is not actually of natural origin, having been artificially created by a race of aliens who live there, not subject to time in a linear fashion.
In the Bajoran religion, the wormhole is worshipped as the Celestial Temple of the Prophets, its builders, who sent out Orbs as contact devices. Since the discovery of the wormhole, space station Deep Space Nine has been moved from Bajor's orbit to be closer to the phenomenon.