A fantastical 13th-century fortification sandwiched by a modern hotel in central Brussels.

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

This solitary monastery may hold the remains of Vlad the Impaler (but probably not).

A forgotten remnant of the Soviet Union, Transnistria is an unrecognized country hidden behind a heavily militarized border between Moldova and Ukraine.

The last king of Poland was interred in this church nearly 200 years after his death.

While the U.S. and Soviet Union were engaged in a space race, Poland built a UFO on the ground.

The two abandoned overpasses are among the largest bridges in Poland.

A tree planted by Marie Curie is treasured by the Radium institute that she set up.

One of the largest amphitheaters in Europe is a former Nazi gathering place that still stands today.

This imposing 20th-century castle was abandoned before it was ever completed.

This man-made mound monument was built out of soil from all across the Polish empire.

Many historians today consider Sverre as Norway's greatest king of all time. 

Sweden's southernmost point is located in this charming fishing village.