India, April 11 -- When the Ancient Greeks first carved steps into a hillside so they could sit around and watch the footraces, they didn't know what they were starting.

By the 7th century BCE, the stadium would become an architectural icon, and far more than just a monument to sport.

The word itself comes from the Greek "stadion", describing the approximately 600-ft distance covered in the ancient footraces. These arenas have long served as sports and entertainment venues, spaces for concert and community, sites of protest and the making of history.

Think of African-American Jesse Owens's four golds at the 1936 Berlin Olympics, with Hitler in attendance; or the Gay Games at San Francisco's Kezar Stadium in 1982. Think of footballer Co...