The Earth Room is a 22-inch-deep layer of dirt spread across a 3,600-square-foot gallery space in the middle of SoHo. Created by American artist Walter De Maria in 1977, it has been a peaceful, quiet sanctuary from the bustle of the street below for three decades, where the mix of smells from the streets of New York are reduced to only one: the rich smell of soil. While there were originally two additional Earth Rooms, both in Germany, this is the last one remaining.

To keep the Earth Room in good shape, curators must regularly water the dirt. Occasional mushrooms have been found sprouting in the 280,000 pounds of dirt. Though it would be a difficult piece to transport and reinstall elsewhere, it is estimated to be worth at least a million dollars. The space itself, in Manhattan's trendy SoHo neighborhood, is probably worth much more.