The Doctor's TARDIS inside the Master's TARDIS. (TV: The Time Monster)
A space loop was a phenomenon similar to a time loop, but in space instead of time. The Third Doctor and the Master were once caught in a space loop when their TARDISes materialised inside each other. (TV: The Time Monster) It happened again when the Fourth Doctor took measurements of the Master's TARDIS while it was in the form of a police box. However, this time it caused him and his companion, Adric, to go through different versions of the console room until they finally managed to exit back into their own. (TV: Logopolis)
Inside Edward Grove, the house turned the TARDIS into a space loop to prevent the Eighth Doctor and Charley Pollard from leaving. (AUDIO: The Chimes of Midnight)
The Eleventh Doctor and his companions Amy Pond and Rory Williams were also once caught in a space loop when the TARDIS accidentally materialised inside itself; it was caused by Rory dropping a crucial component, to be installed in the console, when he looked up Amy's skirt from under the TARDIS' glass floor. The Doctor reversed it by using the Wibbly lever to create a controlled explosion; the space loop involved time travel back a few minutes in the past, which is how the Doctor told himself how to fix it. To prevent the space loop from happening again, the Doctor told Amy to put trousers on. (TV: Space / Time)
When Gregor Van Baalen took a piece of the TARDIS' architectural reconfiguration system, it created several space loops using the corridors, keeping him, Tricky Van Baalen, and the Eleventh Doctor trapped in a labyrinth. (TV: Journey to the Centre of the TARDIS)
