The Forest Gate was the western entrance to the Elf-path that led across Mirkwood to the Elvenking's Halls. It was formed as a sort of arch made by two great trees leaning together that were old, ivy-strangled, hung with lichen, and bearing but a few blackened leaves. Beyond the gate the path became a gloomy tunnel, such that from within the forest the gate appeared as a small bright hole.
It was a four-day ride by horse from Beorn's house directly north to the Forest Gate, which was also to the northeast of the confluence of the Rhimdath and Anduin Rivers. When Thorin and company came to the gate, they camped there overnight before entering the forest. It was at this point that Gandalf left the party, to the consternation of the dwarves and Bilbo Baggins.