Macabre headstones carved with winged skulls, dancing skeletons, and pithy reminders of impending death.

A former waterfront market is now in the center of town due to some interesting Boston engineering.

These azure waters were thought to lead to the Mayan Underworld.

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.

This striking art museum holds an amazing series of curiosity cabinets.

A place to eat for on-the-run agents and espionage enthusiasts.

Home to the world's largest refracting telescope and the birthplace of modern astrophysics.

A bizarre house filled with an astounding array of collections.

This cave holds a surprisingly colorful variety of geological oddities.

A bypass decorated with large wooden troll carvings.

A marvel of Byzantine engineering under the streets of Istanbul.

1513 Turkish world map, full of European state secrets and snarky commentary.

Ancient serpentine sacrifice holder that has stood the test of time.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

Macabre astrological automaton clock dating to the late 1400s.

"World's largest scrap metal sculpture" stands in an outdoor sculpture garden in the middle of Wisconsin.

The park that the Chicago Stockyards built.