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.

A Milanese café entirely designed by the American director Wes Anderson.

Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

The world's largest frame offers spectacular views of the city's past and present.

On any given day this sprawling market houses literally tons of government-regulated gold, gems, and precious metals.

This series of Baroque passageways in Vienna's cultural center mix old architecture with modern art.

Apartment complexes built into huge repurposed natural gas tanks.

The mummified right fist of a 1,000-year-old saint-king sits inside an ornate golden reliquary.

A neo-Gothic church built to thank God for saving the Emperor of Austria from an assassination.

This series of underground chambers contains Europe's largest subterranean lake that is slowly drained each day.

Vienna's giant wonder wheel had a starring role in one of the greatest noir movies of all time.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

The Habsburgs' royal collections of art and wonders.

Legends surround an ancient tree trunk riddled with nails for good luck.

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

Baroque celebration of the end of the Great Plague of Vienna.

Op-art architecture designed for happiness.

A spherical "micro-nation" in the heart of Vienna.

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

The former private quarters and office of Dr. Sigmund Freud now hosts a museum housing the works of the founding father of psychoanalysis.

150 or so scrounged-up lamps, chandeliers, and lanterns light up this alley in central Athens.

This exceptionally well-preserved ancient marvel also houses a small museum dedicated to Jordanian folk tradition.

Replicas of Apollo's leonine stone guard cats still line a sacred row in Greece.