This spectacular track has run continuously since 1882.

A clone of a cloned tree that was so important it allegedly had its own guards.

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

A hoard of sky catalogs, astrophysical journals, even the works of Galileo and Copernicus.

Where the U.S. government kept its actual treasure, before Fort Knox.

A computer bug so primitive it was an actual insect.

The most accurate timepiece in the world.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

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The red brick house where the father of rock 'n' roll wrote some of his classic hits.

A floating museum that was sunk by a flood and left to rot in the tides.

The world's largest Holstein cow.

A lonely house representing railroad history tells the stories of those who rode the rails.

The oldest still-existing mosque in the United States sits in a remote prairie in North Dakota.

A monument to the center of the North American continent may be off by a few miles.

Three legendary, living albino buffalo roaming their pastures for all to see.

One man's quest to save his town with a trail of record-breaking sculptures.

These former Cold War launch sites have been preserved for tourists to see where the button might have been pushed.

"...I guess that was your accomplice in the wood chipper?"

This replica of an 8th century burial ship actually sailed to Norway before returning home to Minnesota.