The Television Centre of the Universe (2013)
Part One
Peter Davison, Janet Fielding, and Mark Strickson hang out with Yvette Fielding at Television Centre where Doctor Who used to be filmed. They visit changing rooms, makeup rooms, and talk about their memories of working on Doctor Who in Television Centre. There are also bits of interviews with other people who used to work in Television Centre that are interspersed with the conversations among the four Doctor Who alums.
There is a second part of this documentary but it is included with the DVD for The Underwater Menace, which seems bizarre to me.
