A truly underground movement

Today, we salute a little-known holiday celebrating an unusual underground cause.

While you may have heard of underground music and the Underground Railroad, this is something altogether different: May 14 is Underground America Day, a day to recognize the subset of North Americans who make their homes in the Earth, not just on it.

Even if you are not a Hobbit, there are huge benefits to dwelling beneath the Earth's surface. Since there's little or no need for insulation, underground houses are naturally energy-efficient, with heating and cooling systems utilizing the Earth's geothermal energy.

Subsurface homes also provide shelter from the elements and forces of nature -- an abode and a storm shelter all in one.

As more people strive to live in tune with their environment, this movement encourages sustainable architecture and green building practices, and the aesthetics of nature are of the utmost importance.

What can you do to celebrate this occasion?

It may not be practical to bury your home, but why not start with small steps? Take an underground tour, or use public transportation -- specifically a subway.

Or begin a green roof project. It technically counts as living beneath ground (or at least beneath soil and plants), while at the same time cleaning the air. And the types of rooftops that can go green are limitless.

Suggested sites:

Directory categories: Geothermal Energy, Energy-Efficient Construction, Sustainable Architecture, Geodesic Domes, Green Roofs

Originally posted on The Spark, a daily blog where Yahoo! Directory editors highlight new and interesting content on the Web.