Now and Then was a multi-episode 2|entertain documentary looking at the filming locations of Doctor Who stories. It looked at the locations at the time of filming and then looked at them in the present. Episodes of Now and Then were released on the DVD of the serial they featured.
For the purposes of this list, a "DVD documentary" is one made especially for the Classic Series DVD range. For this reason, things like studio recordings, film trims/inserts and other documentaries featured on DVD releases are not included below.