The workshop is one of the largest building in the Tower of London, but it is also one of the lesser known. And for good reason, there is nothing special to see, it is, for the visitor, a building like any other.
Of Victorian style it seems to date from the twentieth century, probably a little before when the tower became a purely military place. In the middle of the nineteenth century, the new barracks (Waterloo Barracks) and the officers' quarters (now fusilliers headquarters) were built. The hospital and the workshop are two nearby buildings that arrived a little later.
Location
See also:
The map of the tower of London with the list of the buildings