Greater Rifts Are Coming To Diablo 4 - Abattoir of Zir Explained
www.wowhead.com
The Abattoir of Zir, a new seasonal endgame system coming with Patch 1.2.3 on December 5, seems to work a lot like Greater Rifts in Diablo 3!

players will have 10 minutes to kill enough monsters to spawn and defeat the boss - just like Greater Rifts in Diablo 3.