Root Cellar
From Ice Age Farmer Wiki
Dig a deep enough hole, and you’ll find that the ground is cool (and often moist). Root cellars tap into those cool, moist soil conditions and use them to store produce – like your refrigerator produce bin.
"Mini": Covered Holes
https://www.motherearthnews.com/diy/garden-yard/root-cellars-zm0z11zkon
For Warmer Climates
- http://alanbishop.proboards.com/thread/6084/hot-climate-root-cellars
- https://www.survivalistboards.com/showthread.php?t=25078&highlight=cellar