The abyssal dungeon is a location in the game Lost Ark. It is a dark and dangerous place where players can find powerful weapons and items. To unlock the dungeon, players must first complete the quest "The Black Market." This quest is given by the NPC named Andris in the town of Ark. Andris will send the player to speak with the NPC named Dagon in the city of Eldar. Dagon will give the player a key to the dungeon. The player must then take this key to the entrance of the dungeon and use it to unlock the door.