The Ninjago Caves are a large cave network behind the Ninjago Monastery. Sensei Wu hid the Golden Weapons of Spinjitzu in their various caverns in an attempt to hide them from the invading Skulkin, but the Skulkin eventually broke into the caves and discovered the weapons. Players are then sent into the caves to recover the weapons and defeat the Skulkin. Additionally, the Skulkin have trapped several villagers in the caves, which can be freed by the player to earn rewards.