Template:Location Dr. Who is a special encounter in Fallout.
When the Vault Dweller enters the map, all that can be seen (beyond the usual desert dust) is a large blue police box, common in Great Britain around the 1960's. When the player approaches this strange object, the light on top starts spinning, and the box slowly vanishes with a whooshing sound, leaving behind only a Stealth Boy.
This whole thing is, of course, a reference to the British sci-fi show Doctor Who, and the blue box is the titular character's travel machine, the TARDIS (or Time And Relative Dimension In Space).