This book provides an enjoyable and educational guide to the history, geometry, and practical construction of three-dimensional puzzles. It includes full coverage of the many different types of interlocking assembly puzzles, from burrs, Tangrams, and polyominoes to those using such polyhedra as the rhombic dodecahedron and truncated octahedron. The author, a well-known inventor and builder of solid geometrical puzzles, also describes numerous puzzles designed by himself and other inventors, many never before published. The volume is illustrated with over 200 line drawings and photographs to help enthusiasts build their own versions of these challenging and fascinating interlocking solids. Many unsolved problems are considered that will challenge mathematicians, computer buffs, and puzzle fanatics for years to come.