This shallow cave got its name from copious amount of human bones found inside.

The highest point in Tennessee, Clingmans Dome bears witness to the ravages of one type of insect.

Shop of curiosities with a dinosaur museum tucked in its basement.

A historic beacon built in the aftermath of the worst maritime disaster on the Great Lakes.

Half-sized replica of the Leaning Tower of Pisa built to honor Galileo.

Tour the luxe "glass cage" that inspired and unnerved the architecture world upon its debut.

One of the oldest living oak trees in the Southeast.

South Carolina's last remaining slavery auction house is now a museum devoted to its own tragic history.

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

Nine centuries-old fortresses guard the walls of this medieval Romanian city.

One of the most controversial statues in Romania is an emperor with no clothes.

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

Romania's triumphal arch looks out over Bucharest.

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

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

The bust of Romania’s most notorious ruler, Vlad Dracula aka "Vlad the Impaler," keeps watch over the ruins of his medieval court.

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

Long tunnels run under the ancient chariot racing circuit to the tower.

Go surfing on this urban wave, "hacked" by local surfers.

Pilgrimage site for star-crossed lovers.

The only museum with its curator—and her pets—buried inside.

Two stone columns flank the grand Venice square, but there were supposed to be three.

Go inside to really appreciate this 500-year-old technological masterpiece.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.