The Train Depot is large area located within Gnomeregan, and is the second place players encounter after taking the elevator down from Dun Morogh. It is full of leper gnomes and troggs, and was presumably a transportation hub before the city's networks were destroyed.
The Train Depot leads to the core of the city (the instance) via the Clockwerk Run tunnel to the west. Off the northern-most room (known by some as the Workshop) are: the Loading Room (to the west, now known as the Old Dormitory); and the back door into the instance (to the north), which once could be opened with the , and which leads down into the upper level of the Engineering Labs inside the instance. Namdo Bizzfizzle is also hiding up against the north side of the main platform on the lower level of this room.
In the expansion World of Warcraft: Cataclysm, the Train Depot has become the first part of the new gnomish starting area.