6. Glacier Bay
As recently as 1750, Glacier Bay was an enormous single glacier thousands of feet tall, a mile wide, and dozens of miles long.
But over the last couple of centuries, lower average snowfall and higher average temperatures have whittled away the glacier. It’s down to a fraction of its original girth, about 21 miles long and 350 feet thick.
Margerie Glacier at Glacier Bay National Park.
Because there are no roads at the park, access to Glacier Bay is restricted to boat or aircraft.
However, tour boats can usually drop anchor near the glacier for close-up shots of the ice face and ice calving (when a big chunk of ice breaks off and splashes into the water).