Besides transporting the Doctor from place to place in space and time, the TARDIS from Doctor Who also contained dozens of rooms and other amenities. Debuting in Doctor Who's very first serial in 1963, the TARDIS was a large part of the magic of the series, and the show's reputation grew until it became a cultural phenomenon. No matter which Doctor or which companions were out exploring the cosmos, the TARDIS was the one constant that united all eras of the series, and yet it changed all the time. A ship with endless potential, the TARDIS contained multitudes that were only limited by the creativity of the show's creators.
Standing for 'Time And Relative Dimensions In Space,' the TARDIS was how the Doctor traveled, and yet, the Gallifreyan technology also had a personality of its own. The biggest changes to the TARDIS' exterior were relatively small and mostly cosmetic, but the inside of the blue police box seemed to change with nearly every Doctor that stepped foot in it. So much more than a spaceship, the TARDIS was bigger on the inside which allowed for almost any type of room to be added and subtracted at the whim of the Doctor.
Control Room
Making its first appearance in the season 1 serial An Unearthly Child in 1963, the control room was the first part of the interior of the TARDIS that fans ever saw. Living up to its name, the control room was where the navigational was located, and thus where the TARDIS was "controlled" by the pilot. Even if the Doctor was often at the whim of the TARDIS and not the other way around, the control room was the main room in all of Doctor Who's TARDIS designs. Although the TARDIS also contained unfathomable amounts of other rooms, the bulk of the series played out in the control room.
The Library
Even though the TARDIS library was an important part of the ship in prose, comics, and audio dramas, it didn't make its first appearance onscreen until DW, season 7, episode 10, "Journey to the Center of the TARDIS". Like the rest of the TARDIS, the library was appropriately massive and known to change as much as the control room in shape, size, and design. It contained countless volumes from across the universe, but in its sole appearance on TV it was used as a hiding place for Clara when she was evading the zombies.
Bedrooms
Considering the fact that the Doctor and his companions were often away from Earth for long stretches of time, the TARDIS also contained sleeping accommodations. While many early Doctor Who episodes went missing, the season 1 serial Edge of Destruction remained intact and was the first time that a bedroom was ever shown on-screen. The rooms varied from sparse bunk-style barracks that housed several companions, to veritable master bedrooms for guests, and it was hinted that every companion had their own room at one point. In DW, season 6, episode 4, "The Doctor's Wife", the Doctor was asked if he had a room, but he didn't answer.
Wardrobes
Clothing was always a large part of the Doctor's personality, and their extensive fashion sense came from the TARDIS' massive wardrobe. First seen in the season 2 serial The Web Planet, the wardrobe was packed to the brim with different clothes and would accumulate more with each new incarnation of the Doctor. Many of the Doctor's best outfits came from the wardrobe within the TARDIS, and in the season 12 serial Robot, the Fourth Doctor was shown trying on several combinations before he got it right. The TARDIS contained more than one wardrobe besides the main one and even had a boot cupboard just for the Doctor's shoes.
Cloister Room
Most notable for containing the cloister bell, the cloister room was an obscure corner of the TARDIS that had an ancient design style. Debuting in the season 18 serial Logopolis, the cloister room was visited by the Fourth Doctor shortly before he regenerated. The large space contained benches and stone pillars and was the home of the cloister bell (which rang when the TARDIS was in danger). As the Eighth Doctor reacted to his regeneration, he also visited the cloister room, and the bell itself was seen for the first time in the 1996 Doctor Who TV movie.
Swimming Pool
Perhaps one of the strangest inclusions in the TARDIS was the infamous swimming pool that debuted in the season 15 serial The Invasion of Time. A favorite of the Doctor and companions alike, the pool was often more trouble than it was worth and had to be jettisoned by the Seventh Doctor in the season 24 serial Paradise Towers. When the Eleventh Doctor met Amy Pond in the year 1996, he was wet because he had fallen in during DW, season 5, episode 1, "The Eleventh Hour". Like other rooms, the pool was capable of moving, and in the same episode, the Doctor claimed he didn't know where it was.
Zero Room
Although it only appeared once onscreen, the Doctor's zero room aboard the TARDIS was crucial.Doctor Who struggled with their regeneration in some way or another, but the zero room allowed the Doctor to speed up his healing process in the season 19 serial Castrovalva. The room itself was separated from time and space, and that allowed Time Lords to recover from injuries or illness much faster than they normally would. The room looked very much like the TARDIS control room and featured recognizable circles on the walls and bright white lighting.
Power Room
The science of the TARDIS was always left vague, and exactly how the ship was powered was never fully explained. Even so, the TARDIS contained a power room which was where the ship drew its energy, and it was shown in the season 6 serial The Mind Robber and looked a lot like the Second Doctor's TARDIS console room. Though it was more fleshed out in the prose, the Second Doctor visited the power room in the aforementioned serial, and was able to fix the TARDIS after it had popped out of reality.
Botanical House
Most stories from Doctor Who take place on strange planets and in distant times, but the season 15 serial The Invasion of Time allowed viewers to see more of the insides of the famous TARDIS. The ship's botanical house was featured prominently in the story, and like most botanical gardens its contained a wealth of flora from all across the universe. In the serial, a Sontaran met his unfortunate end when one of th Doctor's planet specimens gobbled him up. The exact side of the botanical house was unknown, but it was certainly one of the largest spaces within the TARDIS.
Art Gallery
Every Doctor was known for their eccentricity, so it wasn't entirely out of the ordinary for the TARDIS to have an art gallery hidden away somewhere. However, the Fourth Doctor's art gallery actually had a secret purpose that was revealed in the season 15 serial The Invasion of Time. When the Sontarans invaded the TARDIS and began shutting its power down, they located an ancillary power station that was disguised as an art gallery. It was shown to feature famous works like the Venus de Milo, though the art all disappeared when the Sontarans turned off the power.