Home to the world's oldest functioning orrery.

An Aztec temple, the largest man-made pyramid in the world, sits buried in earth with a Spanish church set on top.

The archeological ruins of the ancient fortified city of the mysterious Teotenanca civilization.

The jewel of western Mexico's archaeological legacy is this tiered circular pyramid now covered in grass.

The ruins of an ancient pyramid built by the mysterious Chupícuaro civilization.

Three small rooms in the jungle house the most elaborate and intact murals of the Mayan world.

This unusual piece of Renaissance art depicting the bodily horror of crucifixion and skin disease may have been inspired by fungus-induced hallucinations.

The enigmatic and seldom visited ruins of a Mayan city-state.

Rebuilt remains of a temple to Roman god Mithras.

An engineering wonder at Pillnitz Castle protects a precious 230-year-old flowering shrub.

When the rain falls, this drain system turns into a musical instrument.

A unique hanging cable-car navigates through Dresden, the oldest suspension railway in the world.

In addition to fine dairy products, the world's most beautiful milk shop also offers a feast for the eyes.

An exquisite panometer representing Dresden as it was from 1695 to 1760.

The bridge that cost Germany a World Heritage Site.

It is said that each of the white stones in the red facade of this medieval house represents the head of a murdered Swedish noble.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

The library's graceful rotunda is like a bibliophile's temple.

It houses the remains of a 17th-century version of the Titanic.

An intricate and amazing house built by architect Karl Junker.