St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

Real bones which are said to have belonged to a Polish dragon.

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

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

The huge collection of paintings of the American West is one of Denver's best-kept secrets.

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

This Yellowstone geyser may not shoot as high as the nearby Old Faithful, but it erupts for considerably longer.

The only natural lake in the world that drains into both the Atlantic and Pacific Oceans.

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

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

A beautiful geyser under environmental threat.

A small flooded ghost town with a few scattered structures remaining.

The extensive collection of an amateur naturalist.

This museum remembers the tough Mormon trek across America through an intriguing array of artifacts.

Pyramid home to an obscure religious group that practices modern mummification.

A hidden garden of stones engraved with scriptures, a Joseph Smith Sphinx, all carved by one man.

Here lies Lilly E. Gray, an alleged "victim of the beast," but the reason long remained a mystery.

The oldest working bell set in North America, the bells at Old North Church sat silent for their first four years in Massachusetts.

America's original house of worship for Spiritualism, the religious movement based on communing with the dead.

This surreal art house looks like a geometric version of a small chapel.