So there's a keyboard shortcut that hides all objects and only shows the land. I used to know what it was years ago. Now I've forgottten it. But I accidentally pressed it and now I can't see any meshes and the lanscape editing circle brush doesn't even display, there's ONLY the land showing.

I tried some random mashing of keys, but I haven't found it yet.

This is an embarrissing question but does anyone here know what this shortcut is?