Antarctic icebergs often begin as huge table-like slabs of ice that break off an ice shelf. As time goes by, sun and waves erode the bergs, carving them into picturesque shapes. At some point, a berg erodes to the point of instability, and it flops over - exposing even more fantastic shapes.

This flip-flopped iceberg sat just off Point Wild on Elephant Island. This is the spot where 22 of Ernest Shackleton's crew waited on a sliver of rocky beach, huddled under lifeboats, eating penguins and seals - and waiting over four months for "the boss" to rescue them. Meanwhile, Shackleton had an even more challenging time, crossing 800 miles of open ocean in a lifeboat and climbing over high mountains and glaciers to get help. His Antarctic expedition is one of the great adventure stories of all time, and it was thrilling to see one of the places that he and his crew endured.

Lee Rentz