This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

"Unity, Creativity, Beauty."

A striking symbol of the Bulgarian capital.

The beautiful, ornate weather station is the most popular geocache in Salzburg.

The world's oldest known salt mine.

Ride a dragon train into a world of dwarves.

Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

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

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

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

Op-art architecture designed for happiness.

Dine amidst exotic plants at this former royal greenhouse.

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

Danish tourist destination well known for open stalls where vendors sell marijuana on the street.

Copenhagen's celebrated theme park and gardens.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

A little-known cafe in an old copper bridge tower with 360-degree views of the harbor.

This bridge's unique architecture honors nautical heritage and encourages self-awareness.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

Hans Christian Andersen for the postmodern world.

This obscure walkway links Edinburgh’s Old Town with one of the city's prime vantage points.

The fountain marks the area where hundreds of accused witches were burned at the stake.