The gang follows Lincoln's map to the shore and find a group of stacked rocks where they light a signal fire in episode 3x13 "Join or Die". The gang wakes back up on the beach after being kicked out by Luna in episode 3x14 "Red Sky at Morning".
From episode 3x01 "Wanheda: Part 1".
Jax and Nate watch the beach where the Vikings have set up their camp in episode 3x09 "Beebo the God of War".
Blackbeard is burying his treasure on a remote island when is love transforms after donning the Earth Totem. Later he leads Amaya and he new crew to the island only to find Darhk has arrived before them in episode 3x12 "The Curse of the Earth Totem".