If you’ve ever toured an older home and discovered a mysterious little room tucked beneath the stairs or in the basement, you may have found a root cellar.

Before refrigerators and freezers became standard household appliances, root cellars gave homeowners a simple way to keep certain foods cool, dark, and humid. Potatoes, carrots, apples, onions, squash, and other produce could be stored for months without electricity.

Today, root cellars are getting a second look.