Tetrahedral Planetoid, 1954 Woodcut printed from two blocks National Gallery of Art, Washington Cornelius Van S. Roosevelt Collection, 1974 © Cordon Art - Baarn - the Netherlands. All rights reserved. In this print Escher imagined a small planet in the shape of a tetrahedron, or pyramid. Two of the four surfaces are visible and show houses, gardens, trees, roads, and even people.