An acoustic anomaly with a mysterious cause.

A mysterious echo seems to defy the laws of acoustics.

Hide from the tourist hordes in these relatively unknown, and unguarded lava caves.

These picturesque Hawaiian falls are home to a rare species of fish that uses a special sucker to climb up cliffs.

This black shoreline is made up of exploded lava particles.

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

A serene temple with stunning stained glass hides in downtown Dallas.

This "living building" on Georgia Tech's campus is home to a blueberry orchard, honeybees, and more than 900 solar panels.

A whimsical monument marks the highest point in Kansas, not that you could tell by the looks of it.

Once a lonely sentinel on the edge of the Great Plains, this rebuilt trading fort offers a glimpse of life on the Santa Fe Trail.

The largest dinosaur trackway in North America is tucked away among this canyon's ghosts and archaeological gems.