The first declared National Monument in the United States.

Small ship votives hang from the vaulted ceiling of this port-side church with a Latin inscription on the wall.

A mysterious lake provides fresh water without any source, somehow restoring itself from atop its mountaintop perch.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

The fifth-longest suspension bridge the world, connecting one Michigan peninsula to another.

The oldest landmark of Toronto is a testament to shifting sands.

One of the largest underground systems runs under Canada's largest urban center.

This massive, ancient stone was disassembled and then put back together again.

A 6-mile-long lake created by an apocalyptic seismic event and the deadly chain reaction that ensued.