I didn't even know about Meteor Shower in Castle Ironfist. And what's the "special shelf" in Corlagon's Estate?

There appear to be tons of them. Trees, walls and whatnot.

http://www.mightandmagicwalkthrough.com/mightandmagic6/811-hidden-treasures.html

I vaguely remember another site with a list (with overlaps), but can't find it. I do remember though looking for them after finishing the game and going over all the ones that I missed (most of them) just to try them out.

A tree along the shoreline north of the Chime of Harmony Temple gives you a Scroll when you click on it. It is one of a number that have a knot hole. (The area is where the shoreline narrows between the water and the hills.)

The Shelf is in the Estate where there is a bridge through a large room with Ghosts and Skeletons. There is a high up shelf with a candle burning. If you hit it with Telekinesis it sets off a trap. Second time you get some good loot (mid-game loot). There is the wall in the Watch Tower on the fist map. That's right Good Grief. Looks like I missed most of them. LOL. I thought I knew the game.

Which game are you talking about? (That really should be mentioned in the topic title, but it's too late now.)

It appears to be MM6.

I did the necessary edit at the top.
Sorry.

At new Sorpigal, just behind the guilds, before you reach the goblins. Try clicking on the rock on the shore. It is actually a chest with a lot of loot.