Outpost XXIX is built into an Artesian Mound Spring

• Artesian Aquifer: Underground waterways confined above and below by beds of more or less impermeable rock and containing groundwater under a pressure that is significantly greater than the pressure of the atmosphere. This water is capable of rising if given an opportunity to do so.
• Artesian Spring: A natural spring whose water flows from a fissure or other opening in the bed overlying an artesian aquifer. Where the groundwater is forced to the surface, some springs have characteristic mounds which have been formed by the combined action of water, sand, silt and clay and the deposition of limestone from the groundwater. Hence they are known as Mound Springs, and are also called Oases in the Desert.
• Artesian Well: A well that taps into water that is confined in an artesian aquifer.