The Black Cliffs are a series of coastal cliff-faces and stacks located just offshore an uninhabited inner island in the Fire Nation. Their formation creates a natural secluded bay, which Sokka and Hakoda designated a rendezvous point prior to the invasion, as here they were able to easily harbor and hide their naval force.
Team Avatar camped out on the island for the four days preceding the invasion, during which time Aang went into a state of sleeplessness and paranoia caused by his fear of confronting Fire LordOzai. After many failed attempts to calm Aang's mind, the group eventually restored his confidence and sanity through a few words of reassurance and finally got him to sleep by resting him on a bed of koala sheep wool. On the day of the invasion, the naval force, led by Hakoda, arrived at the bay. The warriors were briefed on the details of the invasion plan at the foot of the cliffs, after which they prepared for battle and departed for the Fire Nation Capital along with Team Avatar.