White void

The Doctor looks out into the emptiness (DW: The Mind Robber)

The TARDIS appeared in the White Void when the Doctor flicked an emergency switch in order that the ship could escape a volcanic eruption. Zoe and Jamie found themselves viewing first the void and their images of their homes on the TARDIS scanner, making them believe they had returned to their homes. The Doctor believed, correctly, that some force outside meant to use illusions of their homes to tempt Jamie and Zoe to make them leave the safety of the TARDIS. Zoe, tempted, did leave, with Jamie following after to rescue her. In the Void, the exterior of the TARDIS itself turned white.

Two forces existed in the Void: the White Robots, who captured the Doctor's companions, and the creator of the illusions, who mentally vied with the Doctor's will in the TARDIS console room. The force took over Zoe and Jamie, turning their clothes white. The Doctor broke the force's hold and returned his companions to the TARDIS. (DW: The Mind Robber)

The White Void presumably has some connection with the Land of Fiction which they would encounter subsequently, if not with the Master of the Land.

Another mostly-white void which had zero co-ordinates existed between N-Space and E-Space. It was known to the Tharils as the Gateway. (DW: Warriors' Gate)