Blow molded plastic structures are provided for use in various structures such as, but not limited to, tables, chairs, walls, backboards, storage bins, sports equipment and the like. The blow molded plastic structure has a first surface and a second surface extending between a first end and a second end and forming a chamber there between. A plurality of depressions is formed on the second surface and extends into the chamber. The depressions are usually unitary structures formed by a depression wall. Generally, the steeper the depression wall, the more strength is provided to the structure. In addition, where the plurality of depressions has a low profile and a greater density, increased strength is provided to the structure. The depressions may or may not be joined to the first surface.