The tree is thought to be the oldest oak in Texas and was once crowned state champion for its monumental size.

Dedicated to the art and science of glass in equal measure, this space is as much laboratory as museum.

A local dialect born in the late 19th century is only spoken in this isolated California valley.

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

The whimsical twist of this spire was either caused by the Devil, an unexpected virgin, or lead.

The fairy tale castle of the "fairy-tale king."

Visitors to this library are in for a real-world education in modernist architecture.

The largest island on the great salt lake is home to curious creatures and strange stories.

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

The highest point in South Dakota contains the ashes of Valentine McGillycuudy, the "Holy White Man."

One of America's first dinosaur parks gives a window into Depression-era paleontology.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

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

A lush indoor jungle fills this bustling Madrid transportation hub.

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

A 16th-century monastery boasts a lush array of plants native to Mexico’s most biodiverse region.

The stoutest tree in the world.

A "Texanic" (gigantic Texas) collection of Art Deco architecture at Dallas' historic Fair Park.

This impressive Boston holy house is the American mecca for Christian scientists.

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

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

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

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

Two thousand artifacts from around the world collected by one woman who loved to travel.