A swimming hole in the historic industrial quarry that supplied the marble for the Baltimore Washington Monument.

One man's homage to the orange as realized through a long-term folk art labor of love.

Found: Garden of Eden in Miami-Dade County, Florida.

This spiny beast guards an artist's village while vying for the title of largest lobster in the world.

This abandoned NASA launch site is now a memorial to a trio of astronauts who were killed there.

A building so large that it has its own weather.

Experience a charming 1930's version of "infotainment."

This raised bulls-eye visible from space was the subject of an intense geologic controversy.

Hundreds of drawings left by the land's previous inhabitants remain mysterious.

The fifth-longest natural arch in the world, and the longest outside China.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

Visitors to this arboretum are greeted by three smiling giants crafted from sustainable materials.

This former tuberculosis research hospital endeavored to cure the dreaded disease with fresh air and positive attitudes.

The world's longest known cave system.

Thomas Jefferson's estate is home to hundreds of varieties of historic fruits and vegetables.

Heron, whitewater rapids, and urban industrialism all add to the beauty of this concrete nature walk.

Built by prisoners of war, the largest small-scale model ever built includes eight miles of tiny streams that now sit abandoned.

Pink, packed sanctuary and home of the world's fullest-time Elvis fanatic.

A downtown filled with nearly deserted historic buildings was revived as a pastel paradise.

One of the best-preserved Native American mounds remaining in the southern United States.

A Muppet museum in small-town Mississippi honors the roots of Jim Henson's most beloved creation.

This replica of the Greek structure is in the heart of Nashville.

An ode to "The Queen of Appalachia."