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

An architect's childhood fantasy treehouse made real.

One man's ambition created this psychedelic log home.

An exotic wildlife habitat right off The Strip.

A dazzling display of red rocks weathered into spires and hoodoos.

A well-preserved Ancestral Puebloan ruin tucked beneath a desert cliff.

Vienna's giant wonder wheel had a starring role in one of the greatest noir movies of all time.

The Habsburgs' royal collections of art and wonders.

The topiary maze at the Habsburg hunting lodge.

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

Soaring over the Niagara Whirlpool since 1916.

The best place in the world to buy tinned fish.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

A replica of the beloved character's house, modeled after the author's own drawings.

A catapult rock from Gotland’s 13th-century civil war is still lodged in Scandinavia's best-preserved medieval city wall.

18th century opera in its original splendor.

A golden plaque marks the site of the mysterious unsolved assassination of the former Swedish prime minister.

This trio of stone spires claims to be the only preserved medieval execution site in Europe.

Despite the groans of archaeologists, this astounding groups of Bronze Age petroglyphs have been painted red for tourists.

Although rarely used, there is still a hidden room for the royal family at the Stockholm central station.

Largest island in the Baltic Sea experiences such idyllic weather that roses bloom in the middle of December.