text: What does the signage say? It seems to be serving other premises too, so I'd expect Blue Bell Yard to be the correct name for the access road. Also check the gated footpath presently mapped near the front of the hotel. If this is what https://www.nusatrip.com/en/hotel/united_kingdom/england/greater_london/london/st_james/the_stafford_london_by_kempinski describes as the "secret passageway" and the gates are locked/coded/appropriately signed, it may need an "access=private" tag.