An architect's childhood fantasy treehouse made real.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

A beautiful geyser under environmental threat.

The humble beginnings of one of America’s greatest songsmiths.

An abandoned munitions storage facility with a rich architectural history.

This mansion on an island off the coast of Georgia once belonged to a 108-year-old heiress.

More than a century after her death, Little Gracie Watson remains one of Savannah's most often-visited residents.

This haunting tombstone comes complete with a heartbreaking story of love and loss.

One of Savannah's oldest and most haunted cemeteries, featuring graves desecrated by Sherman's Union Army.

At the most northwestern point of the contiguous United States lies a trail leading through an ancient forest to stunning cliff-side vistas and massive oceanside caves.

You must take the A train... to the last active cemetery in Manhattan.

Pulled from the rubble of one of the worst modern tragedies, a steel crossbeam became a symbol of hope for New Yorkers.

The last living thing to come out of the rubble after 9/11 is now a symbol of hope and resilience.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

Lady Liberty's first beacon of enlightenment is now displayed in a museum near the statue.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.

A smoke stack so large, the Washington Monument could fit inside!

This amazingly preserved Gold Rush town is a historian's dream.

A little-visited ghost town state park offers a glimpse into Montana’s "Silver Queen."

Multiple waterfalls and several historic CCC buildings anchor this state park in Oregon's Willamette Valley.