The Secret Triwizard Challenge

You walk down a path that gets darker as you go, but you can see a faint light glow ahead. You finally enter a glade with four glowing landmarks in each of the corners.
The first landmark is a wizard statue that emits a faint blue light - that must be what you saw from afar.
The second is a golden orchard, from which you can smell all kinds of fruit.
The third is a ring of large mushrooms that appear to be talking to each other.
The fourth is a silver pool, in which you can see something luminous swirling.
The glade's exit is a garden door. You go to it and attempt to exit. Obviously, it's locked. This glade must hold something to unlock it somewhere. You'll have to check all the landmarks.