The only stable wormhole known in the Alpha Quadrant, home to the Prophets.
The Bajoran wormhole is a stable wormhole near Bajor that links the Alpha Quadrant with the Gamma Quadrant, a distance of many thousands of light years. Unlike most wormholes, it does not collapse, which makes it a rare and valuable route between the two sides of the galaxy.
It is inhabited by the Prophets, non-linear beings whom the Bajorans revere as gods. They experience time in a very different way from the humans and other species who pass through it. The wormhole's presence changed the fate of the region, since it brought traffic and importance to a once overlooked area.
Captain Sisko discovered the wormhole in the pilot of Deep Space Nine, Emissary, and the Bajorans came to recognise him as their Emissary. Through the wormhole came the Dominion, which led to the Dominion War, and its protection was a central concern for the Federation and for Bajor. Many of the series' crucial moments revolve around it, including the efforts to keep it open against the Dominion.