Hi everyone! Although this is a topic for Spanish people around (I think there aren't much

), everyone who could know about any sinking mud/bog or whatever similar in Spanish territory o Southern France could participate. I have been looking for mud places or bogs to go sinking, but I have failed in my attempt. There must be dozens of marshes, or even deltas (Am I right?), but I don't know if there is anyone who knows about specific areas.
Maybe this is of no help because many of you live in the UK or the States. But anyway, I should try and ask! Thank you in advance!
Salut!