Sure, sure. Eric mentions that the jungles of Klatch are full of ruins, e.g. lost kingdoms full of Amazonian princesses (which we never see).
Lost gold mines (which, again, we don't see).
We
do meet the Great Muzuma (briefly), but he (she?) is not an Amazonian princess.
As for Klatch: I wouldn't take "Eric" as canon, personally. I think it was "filler", just to get Rincewind out of the Dungeon Dimensions. It's a tasty filler, and amusing, but it doesn't really help to 'build' the Discworld.
To build the Discworld, I would rely more on
"The Discworld Atlas.