Black Hole Shipyards
From Tardis Wiki, the free Doctor Who reference
As noted in the TARDIS Type 40 Instruction Manual, the Black Hole Shipyards were where TARDISes were born and grown.
Following the Timeline Error Incident, the destructive nature of the Twelfth Doctor's regeneration compared to the First Doctor's regeneration was acknowledged by the Time Lords, leading to an investigation by the Black Hole Shipyards. (PROSE: TARDIS Type 40 Instruction Manual [+]Loading...["TARDIS Type 40 Instruction Manual (reference book)"])