TARDISes such as the Doctor's had many generic corridors connecting one room to the next. (Journey to the Centre of the TARDIS) Though varying in appearance, with some appearing to be made of bricks, (TV: The Invasion of Time) the corridors' walls sometimes had roundels like those of the TARDIS control room. (TV: The Masque of Mandragora, Logopolis, Castrovalva, Terminus) Sliding panels could be used to sequester areas of the network. (TV: The Doctor's Wife)
As the connective tissue between the infinity of rooms in the TARDIS, the corridors were always shifting. This made them a labyrinth for anyone who didn't have the special psychic relationship to their ship awarded the Rassilon Imprimatur. (PROSE: How did this creep get in here, Professor?)