Doubtful Sound, Fiordland National Park, New Zealand

Doubtful Sound, Fiordland National Park, Southland, New Zealand, viewed from the Eastern end. Formed by glaciers, the fiord extends 40 kilometres (25 miles) from here to the Tasman Sea. Doubtful Sound was named by Captain Cook in 1770, on the basis that he was "doubtful" whether he could safely navigate his ship in and out of the sound.