NGC 5694 (also known as Caldwell 66) is a globular cluster in the constellation Hydra. It was discovered in 1784 by William Herschel.
This globular cluster is located at a distance of 114,000 light-years (35,000 pc) from the Sun and 96,000 light-years (29,000 pc) from the Galactic centre and is one of the oldest known globular clusters in the Milky Way Galaxy, forming nearly 12 billion years ago.