An aerial view of the Orkney Islands, Scotland, May 3, 2014.
During both World Wars, Scapa Flow was an important British naval base, and the site of significant loss of life.
Following the end of World War I, 74 German warships were interned there, and on June 21, 1919, most were deliberately sunk, or scuttled, at the orders of German Rear Admiral Ludwig Von Reuter, who mistakenly thought that the Armistice had broken down and wanted to prevent the British from using the ships.
Now Scapa Flow is a popular site for divers, who explore the few sunken ships that still remain at the bottom.
This year marks the 100th anniversary of the start of World War I.