Goblin-gate

The Goblin-gate, also known as Back-door by the Goblins, was a stone door serving as the lower eastern passage to the Goblin-town in the eastern side of the Misty Mountains. It was located near the Eagle's Eyrie and west of the Carrock.

The gate was built by the Orcs of the Misty Mountains "ages" ago both as a means of escape from their tunnels and as a way to access and harass the Wilderland. It was always guarded.

Gandalf led Thorin and Company through that exit to escape the goblins. Bilbo Baggins also escaped from Gollum by squeezing through that stone door and losing his buttons.