"its bigger on the inside"
Yes it is, and it also can alter the time,
here is a little back story
You are the doctor, you just regenerated, and you forgot the way around your TARDIS, go exploring, and play with your TARDIS.

Includes:
(intentionaly) faulty time travel (alteration),
Bigger on the inside
Library
Pool
Maze
Regeneration energy (cannot die)
After the dinosaur meteor struck

Adding:
Another teleportation area
more rooms
Sakro
Gallifrey.

FOOTNOTE:
this is what the TARDIS would look like if i was the doctor, also, this is my first time really exploring with command blocks, comment on what I should fix. To change where the tardis is, go into the room by pulling a lever (It will say "Set TARDIS destination) then copy the command and go to under the door, there are two command blocks, put the commands in the one from where you copied them into them and then walk through the doors and it will be a new place