Problem with obelisks

[jigoku]

I've found all but last obelisk (12 of 13) and can't find last one.

I've been everywhere except demon realm, land of dead and murok -> is any obelisk located there? or are they all located in area I've already visited?

Is there any forum/guide/map somewhere with location of all obelisks? I don't like the idea to backtrack every visited location to find out O.O

Any help appreciated!