While watching Jago Hazzard's recent video about the tram subway, it occurred to me that Holborn is the only interchange inside the Circle Line (not including Warren Street) which only has a single entrance and a single exit, but the video mentioned that there was a direct link from the tube station to the tram station. So it seems that there is probably a pedestrian route available from the tube station to the tram station, and from there to a staircase on the west side of Kingsway which must now be covered up at street level. Obviously it couldn't be opened now without making it wheelchair-accessible, but does anyone know if a staircase route under the street is there or mostly there?