Four hundred granite steps were built into this massive rock by the National Park Service.

A sparkling sandstone cliffside that's worth a visit while it still exists.

A super-sized promotional trick that is now a D.C. landmark.

A small but industrious mining operation that allows visitors to touch precious gems while they are still in the rock.

A monumental statue of RCA's mascot now sits atop a historical society roof after a life of moving around.

This beautiful natural train tunnel is said to grant the wishes of visiting lovebirds.

The largest man-made crater in the U.S. marks the spot where we once tested mining with nukes.

A spring-fed pool so deep it's used for scuba diving as well as swimming.

A staggering collection of photographs depicting medical, social, and historical change.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

The home and studio of a visionary woodworker now stands as a museum and example of his artistic genius.