Making a fantasy map of an underground continent [need resources/tutorials]

[Auxilium]

Lets start by saying that ever since I discovered this community I got really excited on the art called "geography".
I'm completely new with this, but more then eager to "master" it.

Now, in the near future I will launch a new continent on a RP-game server. And with that I would love to have a
good looking map with it. So I started searching for tutorials and started messing around with them. The only problem?
I can't find any underground-land-maps tutorials. It is sadly not like a small cave or anything. It is basically a continent
that is completely underground, so the dungeon map tutorials I found here
(or anything related with underground mapping anywhere, really) do not fit my requirement.

Are there any resources/tutorials I could get a hand on regarding this specific kind of map making?

Thanks a ton!

[mystic badger]

When i read your intention, I immediatly thought of two things :
- first, the boardgame "smallworld underground" (pic here)
- second, the underdark in D&D. (pic here)
If I was you, I would searhc a little more on the second topic, trying to emulate the different maps of it (trying a google search, I've found a few extremely different)

Hope it helps !