The Kangaroo and Map Series has long been regarded as the classic issue of the Australian Commonwealth and are among the most popularly collected stamps in the world. The Arthur W. Gray Collection of the Kangaroo and Map Series is, quite simply, the finest and most comprehensive collection ever formed. In fact, not only has it won virtually every major stamp-exhibiting prize imaginable, it is one of the most highly regarded, and certainly one of the most valuable, single issue collections of any country.