Blue Hole (Big Pine Key)
The Blue Hole is an attraction on the island of Big Pine Key in the Florida Keys. It is an abandoned rock quarry that was used for nearby road fills and Henry Flagler's Overseas Railroad. The water it contains is mostly fresh and is used by various wildlife in the area, such as birds, snakes, alligators, key deer and green iguanas. It is part of the National Key Deer Refuge.
Blue Mountains (New South Wales)
The Blue Mountains are a mountainous region and a mountain range located in New South Wales, Australia. The region borders on Sydney's metropolitan area, its foothills starting about west of centre of the state capital. The public's understanding of the extent of the Blue Mountains is varied, as it forms only part of an extensive mountainous area associated with the Great Dividing Range. Officially the Blue Mountains region is bounded by the Nepean and Hawkesbury rivers in the east, the Coxs River and Lake Burragorang to the west and south, and the Wolgan and Colo rivers to the north. Geologically, it is situated in the central parts of the Sydney Basin.