Anti-zone
From Tardis Wiki, the free Doctor Who reference
According to the Thirteenth Doctor, an anti-zone was "a thing the universe [made] wherever the fabric of space/time [was] threatened", acting as a protecting buffer zone.
She went one[statement unclear] such anti-zone through a portal located in a mirror on Norway. That anti-zone separated the Doctor's universe from Solitract plane. (TV: It Takes You Away)