Leoric's Gardens is a secret area in Diablo III Adventure Mode, accessed only through a portal that can appear in any of the five Acts. If the portal appears, there will always be a bounty associated with it. There are four possible events to appear in this zone:
Visually, it is a large combat arena in the ruins of Leoric's Manor Courtyard. Its layout suggests that originally it might have been a PvP battleground.