This large depression in the ground is a typical feature of a karst landscape, formed over time by the action of water on limestone rocks. Due to its shape and characteristics, it functions both as a polje, or "nave," a term used in the Algarve to refer to a wide and relatively flat karst plain, and as a ponor, a type of sinkhole through which water either disappears underground or emerges, depending on the water table's position. These features are commonly known as "eyes of water" or springs and resurgences.

In Várzea do Poço da Figueira, the area is characterised as an open polje, although its contours are poorly defined, indicating that it is in an advanced stage of evolution. The shape and orientation of this depression are clearly influenced by geological faults, particularly visible in the elevations on the southern side, such as the slope of Monte das Assumadas.

The ponor is located at the southern edge of the depression, where water that accumulates can disappear into the earth.