how would you guys (the gurus) created the tardis? just curious :)

hello advanced openglers. after seeing doctor who i thought it would be cool to make his tardis. for those who don’t know what the tardis is its a time machine that is bigger on the inside than it is on the outside. i have no intention of programming it (yet), i was just wondering how you guys would go about programming such a thing. im interested to hear how you guys would do it. (im most interested in how you would do the view of looking into the tardis from the outside)