NGC 2264 designates both the Cone Nebula and the Christmas Tree Cluster, related objects appearing in the constellation Monoceros.
The Chrismas Tree Cluster and the Cone Nebula were both discovered by William Herschel; he discovered the cluster in 1784, and the nebula in 1785.
NGC 2264 is a large, bright cluster easily visible in finder scopes and binoculars. It consists of about 80 stars from 8th magnitude, and spans half a degree. NGC 2264 is embedded in an extensive but tenuous nebulosity, which may be glimpsed with larger telescopes under clear, dark skies. At the south end of the cluster lies the famous "Cone Nebula", an object that is difficult to detect visually.
The cluster spans some 20 light years, and lies about 2,600 light years away. The nebula belongs to a much larger complex, which is currently an active star forming region.