Time Spiral
From Tardis Wiki, the free Doctor Who reference
The Time Spiral was a mysterious phenomenon located in the Time Vortex. The Time Spiral was located somewhere near the end of the Humanian Era.
The Time Spiral could rip apart a TARDIS and anyone inside if it came too close. To deal with this risk, each TARDIS had a device fitted that caused it to materialise any time it came too close to the Time Spiral. However, the Doctor removed his at some point.
The Fourth Doctor, Romana II, and K9 were nearly destroyed by the Time Spiral. (PROSE: The Well-Mannered War)
When the time rotor stopped moving once, the Doctor worried that the TARDIS might have gone right through the time spiral. (TV: The Sun Makers)
