If caves bored into the side of mountains aren’t wild enough for you, you and a guest can sleep 500 feet below ground in Sweden’s historic Sala Silvermine suite. The mine itself was a leading producer of silver during the 16th century all the way to the 20th century when it closed. A network of beautiful underground halls offer unique dining, small concerts, and can be rented for weddings or private parties, which can be arranged around an underground lake.
Cave Palace Ranch in Utah is built into the side of a natural red rock cave, on 110 acres of land. Four interior alcoves have been beautifully transformed into a master bedroom with deck, living room, dining area, two bedrooms and a sleeping loft. The entire home is impressively powered off the grid thanks to a system of solar panels. The window front façade floods the interior with light, while fresh waters is sourced from an underground well.