From Wikipedia: "Omega Centauri ( NGC 5139, or Caldwell 80) is a globular cluster in the constellation of Centaurus that was first identified as a non-stellar object by Edmond Halley in...
M 22 is one of the closest globular clusters to Earth, it is located about 10,000 light years away. It is composed of at least 70,000 stars and its diameter is about 100 light years.