Located on the oceanside, two miles due south of Cudjoe Key, west of Newfound Harbor.

Almost without exception, Spanish charts of the 16th - 18th centuries show in this spot Cayo Cagumas. Cagumas is the Spanish name for the Caribbean Sea Turtle. Several of the 1733 wreck charts show Cayo Cagumas. George Gauld, in his "Observations on the Florida Kays, Reef and Gulf" (1774) quotes a Captain Barton of Carolina as follows: "To Cagavama Kay (southward of the Pinara) W. by S. 1/2 S. distance 3 leagues. To the South of this Kay about 1 league, lies a sand Kay (Kay Looe) upon the Reef." Gerdes, in his "Reconnaissance of the Florida Reefs and all the Keys" states: "The separated key bearing S.W. 2 miles from Bluff Id. (modern Pye Key) is called Loggerhead Kay." U.S. Coast & Geodetic chart of 1868 shows Loggerhead Key. U.S. Coast Survey chart of 1860 also shows Loggerhead Key.

Until 1999, was the site of a commercially operated breeding colony of Rhesus Monkeys.