The world's oldest known salt mine.

Dine amidst exotic plants at this former royal greenhouse.

Handsomely crafted representations of our round planet.

Designed as a reminder of one of the darkest moments in Austrian history.

In the middle of a Vienna square, Roman ruins dating back some 2,000 years are on display.

Baroque celebration of the end of the Great Plague of Vienna.

The historic home of an educator, abolitionist, activist, and poet.

This imposing Masonic temple a mile from the White House was the first public library in Washington, D.C.

A brass and marble scale model of the solar system embedded in the concrete.

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

A small triangle of DC grass is the final resting place of one of Sonny and Cher's songs.

This grand gothic brewery has been pumping out suds for over a hundred years.

A free display of artistic lifesize dinosaur sculptures in a backyard garden.

This location holds the truth to what truly happened that faithful night.

Paranormal experiences in this hotel's room 217 led Stephen King to write "The Shining."

"All Mountains - All The Time."

An impressive collection of over 50,000 minerals including moon rock from the Apollo 17 mission.

The final resting place of American icon Buffalo Bill, and a museum that aids in telling his tale.

This was once the home of Gahan's Saloon, Denver's most storied speakeasy.

One of the greatest heroes of the Titanic tragedy came from humble beginnings to this beautiful home.

An innovative local park built from an abandoned sewage treatment plant.

The oldest operating cemetery in Denver is the eternal home of some of the Centennial State's most famous residents.

The spot in the Mile-High City that's exactly 5,280 feet above sea level (at least for now).

Neal Cassady may still have an open tab at one of Denver’s oldest watering holes.