This presidential tomb was not dedicated until years after Harding's death due to personal controversy.

The childhood home of one of Ohio's favorite sons, pilot and war hero Eddie Rickenbacker.

The home of aviation trailblazers, in a remote corner of the big city.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

The site of Paul Revere's historic two lantern warning.

Macabre headstones carved with winged skulls, dancing skeletons, and pithy reminders of impending death.

A mysterious stone embedded at the base of a historic Boston building.

The American Revolution was galvanized into serious action due to the tragic clash with British soldiers that occurred at this location.

A former waterfront market is now in the center of town due to some interesting Boston engineering.

These delicate buggers are some of the rarest fossils that have bubbled up from the Tar Pits.

An offbeat angle on the ocean viewed through an antiquated lens.

Where NASA's satellites and rovers phone home.

Small plaque marks the spot, but the true center is located about half a mile away on a private pig farm.

The museum chronicling a treasure hunter's dream, fulfilled.

A monument celebrating the idea of reaching inaccessible places.

The famous boat that once ferried Bogart and Hepburn still floats in Key Largo after being abandoned for years.

A geological mystery on Camelback Mountain.

This collection of Wild West movie memorabilia also claims to hold some secrets of the Lost Dutchman's mine.

The world's largest military aircraft cemetery.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

A museum dedicated to the alleged Roswell Incident.

A sign at the end of the Santa Monica Pier marks the traditional end of the legendary American highway.

One of the oldest living oak trees in the Southeast.

This shifting North Carolina sand dune is an odd little desert surrounded by oceanic forest life.