Kanai's Stomping Grounds are a special zone in Adventure Mode of Diablo III, only available for the Udder Cowlamity event in March. It is accessed through a portal created by King Kanai in Immortal Throne within the Ruins of Sescheron (Elder Sanctum) in Act III.
The zone is based on Festering Woods and features hordes of Infernal Bovines, along with a few chests.
Special Zones
Diablo II
Pandemonium Event Zones — Matron's Den • Forgotten Sands • Furnace of Pain • Über Tristram
Easter Egg Zones — The Secret Cow Level
Diablo III
Easter Egg Zones — Whimsyshire (Whimsydale) • Development Hell • Not The Cow Level • The Vault • Kanai's Stomping Grounds