Richard Evelyn Byrd was an American naval officer and polar explorer. In 1926 he announced he had flown over the North Pole (doubts have been raised about whether he reached it), and in 1929 he succeeded in flying over the South Pole. He led many Antarctic expeditions afterward and contributed greatly to mapping Antarctica.
In the world of urban legends, a “secret diary” is told in which Byrd strayed into an underworld while flying over the North Pole and met an advanced civilization, and it is sometimes cited as evidence for the hollow Earth theory. However, the diary is thought to have been fabricated after his death and is not recognized as his own record.