You are looking at a copy of the excellent Melting Block wooden puzzle originally designed by Thomas H. O'Beirne. Fit the 9 exotic pieces of Ash, Walnut, Mahogany, Purpleheart, Wenge, Yelloheart, Beech, Elm, Cherry into a wooden Mahogany box, so that the wood is flush at the top; creating a regular rectangular solid with no internal voids. A popular and quite remarkable dissection.