This pipe (not exactly sure what it is) in my front yard had a divot haloing it. About a month ago i filled it in with some topsoil and now i have this mushroom growing.

I'm curious what kind of mushroom it is? If i should do anything with it? And why it might be growing there?

Aesthetically it doesn't bother me too much at it's current size. I understand that it's helping decomposition so can i just let it finish it's job up? I'm guessing adding the topsoil helped foster it's growth, there was also a large oak tree about 20 feet away ~2 years ago.