Hadas IV was a planet located somewhere in the space of the galaxy's Alpha or Beta Quadrants, the fourth planet in orbit of the Hadas star system, known for its sulfuric mines.

In 2369, when looking at the desolate landscape he was seeing in the Bajoran wormhole, Benjamin Sisko commented "It can't beat the sulfuric mine pits of Hadas IV". (DS9 novelization: Emissary)