This is that famous blue box that the Doctor uses for his travels through space and time. The name stands for “Time and Relative Dimensions in Space.” This contraction was made up by the Doctor's first companion, Susan Foreman. As anyone who has ever walked (or stumbled) into the TARDIS has pointed out, “it's bigger on the inside” – much bigger, in fact. What looks like a small police box, is actually a gigantic spaceship, complete with a library and a pool. As far as its iconic image, the police box, goes... that was actually a mistake. A properly-operational TARDIS is supposed to automatically disguise itself wherever it goes. In ancient Rome, it would turn into a pillar, in prehistoric times, it would become a rock. Unfortunately, the Doctor's TARDIS broke. It landed in 60s London, disguised itself as a police box, and has been stuck that way ever since.