A Romanian church built from one single oak.

Gigantic Romanian salt mines used to heal respiratory conditions.

This bone-filled cave got its name after they found 140 bear skeletons inside.

This snug medieval lane is one of the narrowest streets in the world.

A muddy alien landscape that is home to rare species of exotic plants.

The romantic botanic tunnel feels like a well-kept secret.

Romania's "Red Ravine" is a little-known natural wonder that bears a resemblance to the Grand Canyon.

No one knows who built this strange cave of worship or exactly why.

Conspiracy theories and occult legends surround this mysterious natural rock formation.

A giant portrait of an ancient king looms over the river.

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

The legendary cliffside castle of three-time Voivode of Wallachia, Vlad the Impaler.

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

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

Once an opulent Art Nouveau hotspot, the Constanța Casino is one of Romania's most beautiful abandoned buildings.

This massive underground salt mine now holds a sci-fi theme park in its depths.

This fairy-tale castle would make Dracula (who is said to have been imprisoned there) jealous.

A playing field for a popular French past time can be found tucked away in a quiet corner of Golden Gate Park.

The key to turning shifting dunes into the green oasis of Golden Gate Park.

A famous alternative culture epicenter and where Joplin serenaded young hippies.

San Franciscans leave gifts and messages for the magical beings that live behind the tiny, mysterious door installed on a tree in Golden Gate Park.

A mysterious painting of the self-declared Emperor of the United States watches over a local hof-brau.

The giant pair of sexy legs sticking out the window of this costume store have become its main draw.

Since 1973, this block has been home to the most concentrated collection of murals in San Francisco.