Serious Puzzles may sound like an oxymoron, but it’s actually a very apt name, since working puzzles and figuring out brainteasers are great ways to boost your thinking skills. At Serious Puzzles, you can shop for all different types of puzzles, including jigsaw puzzles, puzzle boxes, puzzle cubes, disentanglements, 3D puzzles, assembly and interlocking puzzles and puzzle books. Founded in 2002 as a small family, home-based business, Serious Puzzles has grown to become the leading online puzzle retailer. The site is focused on offering products with great prices and with excellent customer service. Shop by theme, number of pieces, brand, age recommendation, difficulty or price. Find puzzle collections that are made in the USA, are eco-friendly, or that sell for only $5. The site also carries accessories like puzzle storage and frames, and other cool stuff, including glow-in-the-dark spheres, jumbo building blocks, fractiles, yo-yos, plasma cars and zip line kits.