This 8th-century Bavarian monastery is home to an exquisite Baroque-era library.

This former steel and coal plant is now a neon-lit industrial fantasia.

A castle from the Holy Roman Empire that hosts traveling youth... in its stables.

This 3,800-year-old site contains markers used to study the movement of the sun and moon and create a lunar calendar.

A Neolithic celestial calendar standing in a nondescript wheat field.

The mysterious megaliths have enchanted and intrigued visitors for thousands of years.

Called the "Armenian Stonehenge," this ring of menhirs pierced with holes may be a prehistoric astronomical observatory.

A sophisticated astronomical tower built by one of the greatest Persian scholars of the Islamic Golden Age.

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

A phenomenal assembly of pueblos in New Mexico is the most complete example of ancient ruins north of the border.

Light still pours into the ruins of this ancient Islamic observatory.

This ancient Chinese observatory still contains early astronomy technology.

The remains of an entire Roman city can be explored in this interactive museum.

An industrial site turned into Hungary's most cherished natural wonder.

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

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

A 19th century artistocrat's mansion, turned into a library, hidden in a modern library.

This solemn facility remembers the cruel effort to compel Native American children to relinquish their culture.

One lonely, modern pyramid has gone from corporate think tank to deserted boondoggle.

An easy-to-reach, century-old shipwreck in shallow and crystal clear waters.

Faces carved into the cliffs create an otherworldly walking trail.

A collection of Witchcraft artifacts and occult paraphernalia started by the leader of the Long Island Coven.

Abandoned since the 1950s, the streetcar lane beneath the heavily trafficked bridge lays empty and unused.