Planet (The Timeless Children)

The Timeless Child was found on an unnamed planet by the First Tecteun. (TV: The Timeless Children)

Appearance
The planet appeared to have a purple sky, and a sand colored structure. (TV: The Timeless Children)

History
When first mentioned the Timeless Child mystery to the Doctor, she got a massive headache and a flashback to when the Remnants approached her, as well as a glimpse of a child wearing yellow robes and standing outside a tall building under a purple sky. (TV: Spyfall)

While aboard a space platform in the far future owned by Zellin, the Doctor, after having fallen unconscious due to Zellin's powers, dreamed about the vision of the Timeless Child while the Master's message to her echoed in her mind. In this scenario she was actively present in the vision. (TV: Can You Hear Me?)

The Timeless Child was eventually revealed by the Master to be a child discovered on another planet who had the power to regenerate infinitely who had come through the Boundary, a gateway leading to another universe or dimension. The child was adopted by the First Tecteun, an early Shobogan space traveller who brought her back with her to Gallifrey. (TV: The Timeless Children)