The Spiral Cellars come complete with trap doors, and makes the very best use of the earth to insulate and create good storage conditions for wine.
The hole is dug neatly and then the storage area is created from concrete wrapped in a watertight lining. Passive ventilation keeps the temperature around 13° Celsius/55° Fahrenheit, the ideal temperature for wine storage.
Several sizes are available, holding from 1000-1600 bottles. The cost is approximately $30,000 USD, which is a small drop in the ocean for wine lovers.