It's hard for the curious visitor to enter the expansive central London HQ of the Honourable Artillery Company (HAC) undetected: you can't get in without showing some ID. You also need to dress appropriately to gain access to a building which, in keeping with tradition, still houses a variety of arms and ammunition.

Indeed, tradition is the watchword here at Armoury House, which was built in the 18th Century. These days, it can be