|Messier 15 in Pegasus.|
In fact, that enormous number of stars includes some interesting things, including 112 variable stars, 8 pulsars, and a planetary nebula. This was the first planetary nebula (which have nothing to do with planets besides appearance in small instruments) found in a globular cluster, and one of only four located in globular clusters found to this point. It is also thought that there may be a massive black hole in the center of this cluster. So all in all, a bit more interesting than some of the clusters I've focused on recently.