The Royal Horseguards Hotel, near Northumberland Avenue. Nowhere to legallly park, load in down a narrow set of concrete stairs into the basement, through the kitchen (whilst they were doing a live table service) dodging portuguese waiters, up 2 floors in a cranky goods lift with those slide-across doors (also being used for the food service) and into the venue.
Load out much easier, the Liberal Club which also forms part of the building had closed so we were allowed to load out down the huge front staircase.