A disquieting Aztec sculpture displays hundreds of stone skulls representing the victims of human sacrifice.

A museum in the former home of Marxist revolutionary Leon Trotsky.

A magical sinkhole on the Yucatán Peninsula is adorned with mini waterfalls and hanging vines.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Every equinox this Maya pyramid puts on a spooky ancient light show.

Superstitious? Discover the witchy side of Mexico through its largest esoteric market.

Frida Kahlo's childhood home, now a museum of her life and works.

An island filled with hundreds of hanging, decomposing, decapitated dolls.

Avoid gangster interaction while window-shopping.

A bit of retro transportation flair preserved in the world's largest department store.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

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

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

Check out engineering marvels of the past at this unintentionally retrofuturist museum.

Romania's triumphal arch looks out over Bucharest.

A celebration of all things tacky, garish, and bizarrely creative in the Romanian capital.

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.

The preserved arm of a third-century sorcerer is believed to have the power to lift curses and spells.

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."

Video games, body language, and postal history are all on display in this Swiss museum.

Natural history museum displaying a famous taxidermied St. Bernard.