Grymforge has an elevator up to the surface that takes you to moonrise/the land near moonrise. Moonrise seems to be act 2. Even the chreeche seems to be a optional part of act 1.
actually, according to datamining, that elevator takes you to the ancient sharran temple that Nere is looking for. Maybe it was leading you to the surface but something went wrong and it it dropped you to the lower level.
