Nothingness: You can always track down the piece you've seen once by looking at the move list on the right, so the pieces might as well stay visible. You could replace the vulcanoes by these grey spots. This way you can move the pieces already seen without further revealing and choose to reveal more to gain more movement freedom. I like the idea!
(hide) If you only look at some of the discussion boards on a regular basis you can add them to your favourite boards list by going to the Board page and clicking "Add to my favourite boards". (pauloaguia) (show all tips)