Re: How Big is the Eye of Harmony? (spoilers Journey to the center TAR The entire interior of the TARDIS is in another dimension. The interior of the TARDIS may exist along way from the big city of our universe. Not just some subdimensional boondock of our universe, but practically or literally another universe which is how the Doctor can claim that the interior of the TARDIS reaches out infinitely. Rory explained this. The Tom Baker one where they walked into a movie on a space ship too.