The jars, also known as "tinajones" or "gigantas" when they were made 3 meters high, were entirely handmade pottery in the area, using local clay extracted through wells practiced in the fields. Not only were used to store wine, but also to preserve olive oil and a variety of solid products such as cereal grains. Caves like these used to be dug under the houses, drawing labyrinthine tunnels in various directions and at various levels. The huge jars could contain large quantities of wine, both for private consumption and to sell its production to the market. The caves were being dug as needed. While new tunnels opened, certain sections collapsed or were closed.

Subsoil environmental conditions [temperature, darkness, silence or humidity] much more stable than on the surface, favoring the temp control during fermentation, maceration or food preservation.

More modest caves, popularly called fresqueras, were also built as part of the needs of a family home. It was the most sustainable way to keep agricultural products at reasonably cool temperatures in a peninsular region with extremely dry summers where temperatures can exceed 40 ° C. The subsoil moisture is not due to rainwater, but groundwater circulating through these limestone lands, sometimes outcrops through small springs or large aquifers. In these villages, the water extraction well was usual.

Ventilation ducts caves also served to cool the most exposed to heat rooms, acting as a modern air conditioning. By contrast, the same thermal sensation of coolness in summer, becomes warmth in winter, when temperatures drop below zero on the surface. The stabilized temperature of the caves, just over 10 º C, is experienced as heat or cool depending on the season