Part of the Chac Mool system, the entrance is a couple of hundred feet away from Cenote Chac Mool.  Access to the Kukulkan cenote is  through a beautiful pond at one  end of the cenote.  At approximately 10 m, you will be entering the halocline zone.  Shine  your light to the point were salt and fresh water meet and marvel at the reflections projected on the walls of the cavern.  The dive passes through a huge cavern that surrounds the cenote.  The light effects are amazing, as  sunlight penetrates the darkness.  Take a moment to look towards the ceiling at the entrance to see the colors of the rainbow.
Kukulkan and Chac Mool cenotes are connected by a restriction.  It is forbidden for cavern divers to cross from one to the other through this restriction.