I've seen several recipes for pain de cristal (glass bread) lately, a very high hydration dough, Jimmy Griffin's youtube page shows him folding some that is 114% hydration. King Arthur has a recipe that is 100% hydration and goes through as many as five stretch and folds to strengthen the dough as it matures.
Probably won't try it during the summer heat wave, but I might try it in a month or two.
I've worked with a few high hydration doughs, Peter Reinhart has a baguette dough that is around 80% hydration as I recall. This one seems like a serious challenge, one I will likely attempt once the weather cools off a bit.
There are some high hydration pizza doughs I've been meaning to try, too.