Impossible sculptures
Aldo Cavini Benedetti (aldoaldoz)
Artist's Flickr photostream http://www.flickr.com/people/aldoaldoz/
This is the real model of the construction from Escher's lithograph "Ascending and Descending". The model was created with Geomag toy constructor. You can see video about this model.
A model of Escher's Waterfall,
which was created with magnetic constructor.
See also photomontage of impossible summerhouse.