Whilst the exterior shots of Southwark Cathedral are the cathedral itself (or a matte image edited onto the Cardiff exterior sets), the interiors were filmed in Wells Cathedral (apart from the tower as seen from the crossing and the interior of the tower, which is a set). A model of Southwark Cathedral also appears in Lazarus's office, along with one of Michelangelo's "David". The interiors of Professor Lazarus's institute were shot in Cardiff Museum, the Welsh Assembly's Senedd building, and St William House, Cardiff. The latter also served as a location for the pilot episode of "The Sarah Jane Adventures", and the "Torchwood" episode "Random Shoes".