Map:Peninsula Map (Atlas of Worlds)
Connected patches of land using act2 grasslands tilests and having a generally unremarkable layout. The boss is a giant shambling rockpile enemy with additional life and the allies can't die aura. He has some backup, so approach carefully. You'll find him on a spit of land entirely behind a ruin wall with some backup, so be careful. Be aware, though it doesn't look like he should be able to, he can walk through the gate in said wall.