Wells (synonyms: water hole, reservoir, cistern; example toponyms: the Old Well, the Wishing Well) are sites where natural ground water is connected to the surface so that it may be accessed and used. Wells are especially important in desert regions or other areas where water may be hard to find. Fictional wells may connect to extensive cave systems below, underground rivers, or the sewer system. In fantasy worlds, wells may be magical themselves, granting wishes or acting like portals to another place. Wells may be enclosed within a wellhouse. They are a related element to cisterns.

When designing wells consider how deep they go, how accessible water is in the surrounding area, and whether the well is full or empty.

Wells, if contaminated, may spread disease.