Sinkhole of evil

[Gransoley]

While scrolling through old forum threads i came across a post talking about the existance of sinkhole of evil from ravenloft and them giving undead +3 to +5 turn resistance.
Is there really a mention of this in 3e ravenloft book or DrM or whatever?
If so I couldn't find it with a quick scan.

[MaxiDuRaritry]

Ravenloft Player's Handbook p107?

It's in a rather thick sidebar.

[ShurikVch]

It's in the Ravenloft: Player's Handbook... I was swordsaged!..

Also check the Lingering Effects of Evil in the Book of Vile Darkness, and "Not For the Living: Six Haunted Templates" in Dragon #336