TARDIS laboratory

The Doctor's TARDIS had a laboratory.

Layout
The laboratory was around the size of a school assembly hall, when Barbara Wright visited it once. It had lines of long wooden benches covered with a variety of scientific instruments, from Chinese abacuses, to test tubes, to items from Barbara's future she didn't recognise. It also had a wall lined with computers, another wall with diagrams and charts, and a third wall with huge shelves full of files, papers, and books. (PROSE: The Edge of Destruction)

History
While staying in London, on 31 March 1963, Susan came home from school and tried to find the Doctor. She searched both his laboratory and the control room, but found him in neither. (PROSE: Time and Relative)

During the time the TARDIS was immobilised and everyone was acting strangely, Barbara Wright found the TARDIS laboratory. There she was assaulted by books, boxes and various bits of equipment from the benches. (PROSE: The Edge of Destruction)

Amy and Tony Barker once accidentally stowed away in the TARDIS, and unintentionally locked themselves in the Doctor's laboratory. Later, the TARDIS landed on the Sense Sphere, and the First Doctor used his laboratory to synthesise prussic acid, which he then used to kill a Zilgan. Unbeknownst to the Doctor, Tony had been observing him from underneath a bench in the laboratory. (PROSE: The Monsters from Earth)

The Third Doctor once recalled a time when he created a gas in the TARDIS lab which pacified a herd of rampaging volcano creatures. (COMIC: The Arkwood Experiments)

The Doctor who visited Karn with Jenny Wilson and Jimmy Forbes altered one of the fragments of the Crystal of All Power in the TARDIS laboratory while it was in his possession, thereby sabotaging the Daleks' intended use of the Crystal. (AUDIO: Seven Keys to Doomsday)

When Ace was new on board the TARDIS, she explored its interiors and found the lab. She thought it was similar to Frankenstein's lab, but with better lights. Ace didn't tell the Seventh Doctor she found it, because she knew he'd lock it up to keep her from making Nitro-9. She couldn't always find the place afterwards. (PROSE: Echo)