The Lycanthrope Grounds are two separate dungeons which are infested with creatures which have been contaminated by the were-sickness of Grimvale. The two dungeons are connected to each other by a Death Portal, meaning you can enter from Edron and leave through Cormaya and vice-versa.
It's a good hunting place specially for mages of level 100+, usually in small teams, using Great Fireball Runes. Because of the high amount of summons used by the creatures (Foxes, Badgers and War Wolves), their invisibility (Werefoxes and Werebadgers) and the fact that Werefoxes stay at distance, it's not a very good place for Knights to hunt, specially solo.
The Grimvale Quest - The Curse Spreads takes place mostly around these caves and is required to access the boss rooms as well as to use the portal between the two dungeons.