This ancient Roman bridge and aqueduct still stands as a wonder of classical construction.

Twenty-seven massive radio antennas on the high plains of New Mexico search for life on other planets.

Earth's tallest volcano is sacred to Native Hawaiians, and home to a dozen world-class observatories.

A world-class observatory in the California desert.

The world's first permanently occupied mountain-top observatory continues to report on the stars.

This former stomping grounds of the most eminent astronomers of the early 20th century.

In the most arid desert on the planet, the world's leading telescope allows astronomers to see more than has ever been seen before.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

An homage to everyone's favorite prehistoric cartoon family.

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.