The cover page of Douglas Hofstadter's international bestseller is probably one of the best known examples of ambiguous objects. Each of the wooden blocks casts three shadows : the first letters of Gödel, Escher and Bach. The author calls them trip-lets. Number of ratings : 20.
The Playful Eye Is it a crone or a lovely lady? A dapper man with a ascot or a toothless old geezer? Things are not always what they seem at first glance...or even at second or third. The Playful Eye is a virtual feast of games and visual tricks gathered from around the world.
Seeing Double Seeing Double is about all the ambiguous stuff you can find here. The ambiguous images are shown together with the upside-downs which you'll also find somewhere else on this site.