8th Ed. Temple of Skulls

[Kadzik]

We are making campaign for Mordheim in Southlands and we have found place called Temple of SKulls (in the eastern part of Southlands, nearly on the equator). I can bet I've read about this in some old Lizard codex, and this is ruined Old One's city, but I'm not sure.
Does anyone have some more information?

 

[Guardian of Hexoatl]

I know I've heard mention of it but I can't for the life of me dig up any information on it though. Even Lexicanum is drawing a blank on it!