The 19th century was the heyday of steam railways.

At the height of the Cold War, for example, scientific organisations provided a conduit for discussing nuclear weapons control.

But health care for all was, even in the heyday of the Great Society, a step too far.

At its peak, the grounds of the Imperial Palace in Tokyo had a greater theoretical value than the entire state of California.

And did the ancient Maya - whose empire peaked between A.D. 250 and 900 in what is now Mexico and Central America - really predict the end of the world in 2012?