When deciding where to build the Oracle at Delphi, Zeus wanted to build it at the center of the earth. The story is that he threw two eagles into the sky. They flew at equal speeds in opposite directions, where their paths crossed was marked with a stone called the Omphalos, which means navel of the earth. This is an abstract interpretation of the story.
31.5 x 31.5 x 21 inches, weight circa 900 lbs (without plinth), Statuary Marble of Carrara