So, according to Eris, Lake Vanessa is one of the larger dungeons within a much broader complex called the Vanessa Dungeon Cluster, which includes five major dungeons and thirteen smaller ones. This entire cluster was first discovered—and partially explored—by Lady Vanessa Loren, the second Guildmaster of the Mistvale Adventurer's Guild, many, many years ago.
Essentially, dungeons can exist within other dungeons. In some places, dungeons connect to each other like a network: sometimes only one or two link up, but there can also be dozens or even hundreds interwoven together. It's similar to the way branches grow on a tree, creating a sprawling system known as a dungeon cluster.
