Destroyed Serbian army headquarters sits half crumbled in a largely revitalized Belgrade.

A misnamed well, with a deep dark past.

A towering spire in the fortress of Kalemegdan honors the victorious armies of Serbia during their struggles against the Ottoman Empire.

Nikola Tesla's ashes are held in a golden sphere, surrounded by his works.

This giant crucifix is like U2's Joshua Tree for Swedish death metal fans.

The library's graceful rotunda is like a bibliophile's temple.

It houses the remains of a 17th-century version of the Titanic.

An illuminated manuscript comprising the life's work of a lone monk, inexplicably decorated with a portrait of Satan himself.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

Rolling sand dunes of the Sahara... in the middle of the Atlantic Ocean.

This ship carrying cargo and four church bells for the Catedral Metropolitana Nossa Senhora Aparecida ran aground in 1968.

Iron Age grave stones and Viking burials, a short drive from Gothenburg.

Copenhagen's celebrated theme park and gardens.

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

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

This chimerical bridge/tunnel appears to dead end right into the sea.

A Very Low Frequency transmitter you can tune in on your PC.

Hundreds of mossy stones engraved with bits of philosophy, literature and random musings.

Swedish skyscraper with a 90° twist.

This cobblestoned medieval-style town was entirely constructed in the 1990s and 2000s.

Old Danish castle immortalized in Shakespeare's Hamlet.

This Swedish astronomical clock was in storage for almost a century before its glorious workings were put on display once more.

According to legend, this boat-shaped henge is built over the grave of a mythic king.