This fantastical waterfall is hidden in a cave located in a cracked cliff.

Iceland's largest lagoon is home to stunning multi-colored icebergs.

A saloon and inn that served the Wild West's most iconic figures—and is still haunted by some of them today.

The oldest continuously occupied public building in the United States.

This giant pocket watch is the third iteration of a local landmark that has been standing just off the Santa Fe Plaza for over 100 years.

This tea house was a hand-built gift from Boulder's sister city in Tajikstan.

From banquet hall to Masonic Lodge and now concert venue, Ganz Hall is a breathtaking glimpse of into the golden age of American architecture.

This urban drawbridge gained eternal pop culture fame when the Blues Brothers jumped it while it was raised.

This historic hotel invented the chocolate brownie.

The last masonry skyscraper ever built reveals a transitional moment in architectural history.

These chunky stone towers out in Lake Michigan are the key to Chicago’s drinking water.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.

This surprising gem is a world-class archeological museum hidden at the University of Chicago.

This $3 million model train takes you through Chicago, Seattle, and the thousands of miles in between.

Illegal drag racing two stories beneath Chicago’s streets.

What's left of the ruins of the 1893 Columbian Exhibition, or World's Fair, also known as the White City.

The only Bahá'í house of worship in North America and one of only a handful worldwide.

A lush green oasis in the middle of Chicago.

This verdant, tree-lined Reykjavik graveyard is both enchanting and eerie.

Walk in the footsteps of the gods and straddle two tectonic plates.

L. Frank Baum wrote part of the "Wizard of Oz" series in this wooden Victorian beach resort.

An off-the-beaten path cave with an underground lake.

The final resting place of the businessman-turned-astronomer who helped discover Pluto stands near his observatory.

Giant telescope mirrors built in a spinning furnace under a college football stadium.