Cliffs that hold fossils, including the earliest known reptile, dating back more than 300 million years.

The biologist's fossilized headstone was meant to reflect his love of nature. Its, ahem, unusual shape is probably just a coincidence.

A well-preserved Ancestral Puebloan ruin tucked beneath a desert cliff.

Ancient pueblos built into the base of a natural canyon wall.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

Seemingly grown on some other world, these New Mexico rock formations look like a disused science fiction set.

A multi-storied adobe complex has been inhabited for more than a thousand years.

A small metropolis of Pueblo cave dwellings have been carved right into the hillside of this national monument.

The remote island home of the overlooked explorer who co-discovered the theory of evolution by natural selection.

A treasure trove of astronomical, mathematical, and scientific instruments at Cambridge University.

Remote, volcanic island that Darwin, Hooker, and the Royal Navy shaped into a thriving, artificial ecosystem.

Eighty million natural history specimens call this gargantuan museum home.

Repository for more than 22 million pickled specimens.

The Origin of On the Origin of Species.

A well-preserved 2nd century fort where moles are the archaeologists.

A unique museum tells the story of the day-to-day life of World War I soldiers.

This modern French ossuary contains the jumbled bones of 130,000 WWI soldiers.

Site of one of World War I's most horrific scenes.

A moving memorial to the fallen and missing from WWI trenches.

The site where one of the most famous poems of World War I was composed is preserved to honor the legacy of the work.

In an area where the remnants of WWI are discovered on a regular basis this preserved frontline trench may be the most amazing.

An ancient instrument used to measure the waters of the Nile so Egyptian farmers would know whether to expect famine or flood.

An ancient city exhumed from the depths of the ocean.

A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.