A well located at the bottom of a slanted aquifer such that the water goes downhill with gravity, then up the well. No energy is required with this type of well.
This type of well is known as an artesian well. Artesian wells occur when there is enough pressure in the aquifer to push the groundwater up through the well without the need for pumping. The pressure in the aquifer is typically caused by the weight of the water trapped between impermeable rock layers. When a well is drilled into this pressurized layer, the water is able to flow upward to the surface on its own accord.
Artesian wells are prized for their reliability and constant flow of water, as they are not dependent on external energy sources to pump the water. However, it is important to note that the pressure in an artesian well can fluctuate depending on conditions in the aquifer, so monitoring and management may still be necessary to ensure a consistent water supply.