An eerie, derelict amusement park in Berlin.

Some call this eerie forest of crooked trees the "Bermuda Triangle of Romania."

Something's watching you.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

The possible imprisonment of Vlad the Impaler here earned the medieval castle its nickname, "Dracula's Castle."

A fire once nearly devoured this gorgeous 14th-century Gothic cathedral.

The European towns of Brașov and Râșnov each have proud signs reminiscent of the Hollywood sign.

This elaborately decorated, fairytale-like Romanian royal palace is one of the most striking castles in Europe.

This memorial to the victims of the Romanian Revolution of 1989 is often compared to a potato on a skewer.

Romania's triumphal arch looks out over Bucharest.

This beachside town is home to a diverse nature reserve, multiple cays, and one of the three bioluminescent bays in Puerto Rico.

Stone Age solar temple is aligned with the sun on each equinox and solstice.

This unique building in the main square stands out among the city's typically Baroque architecture.

The ancient heart of Tunis is an enormous maze of narrow streets and alleyways.

An ancient burial ground believed to have been used for ritual sacrifice.

An ancient Phoenician citadel once stood at the site where Queen Dido first landed, according to legend.

Sleep in a climate-controlled plastic bubble for the night.

This collection of over 50 murals celebrates Brussels' rich history as the self-proclaimed home of the "comic strip."

A little sculpture with a large wardrobe.

Thermal springs underneath the seabed provide the heat and bubbles for these beachside natural hot tubs.

This historic hiding place, often used by people escaping slavery, is a testament to a heroic struggle for freedom.

The smaller of the three towers of San Marino is a former prison inaccessible from the ground level.

The oldest-known example of a historic architectural style recognized by UNESCO.

The largest Roman amphitheater in the Balkans once held over 20,000 people, but managed to lay hidden for hundreds of years.