A feature shared by the
TARDIS (of the
Dr. Who series) and the house of
Wonko the Sane (of
The Hitch-hiker's Guide to the Galaxy).
Dr. Who's time-and-space-travelling vehicle appeared to be a mere phone booth from the outside, but inside housed a whole lot of, well, stuff.
Wonko the Sane's house was turned inside out -- what you would usually expect to find outside a house (the yard, exterior paint, etc.) was on what was structurally the inside and everything you would expect to find on the inside (wallpaper, furniture, carpet, etc.) was on the structural outside. The whole thing curved around in a very Escher-like way so that standing in the outside made it look like the whole world was inside the house and you were outside the world.
Interesting to note that this idea seems to have a common origin in the
UK.