Can't Delete A Thingy!

So I have this thing on my map that I want to delete but I can’t do it. I can’t remember if it’s a unit or doodad or some kind of environmental prop. It won’t even highlight to tell me what it’s name is. All I can tell you is that it’s the hole from the Dominion artifact dig site in Terran Campaign Mission #2. The hole, not the big yellow crane that fits on top of it. I was able to delete the crane with no problems. How do I delete the hole?

Choose decoration on top of Surface editors. Try to click now.

It might be a terrain object in the terrain editor.