WoWDB

Caverns of Time: The Black Morass will be making its return to current content via the Timewalking system introduced with Patch 6.2.  All players level 71 and above will be able to queue for the Timewalking version using the LFD tool when the special event is active.  The official highlights blog is here.  Don't forget to pick up A Burning Path Through Time.

Important note:  If your character is Goblin or Gnome, plan ahead and use a tall mount or quaff a water-breathing potion (or equivalent).  The pools of water in the swamp are deep enough that short-stature folk will swim in them and even drown in them.