Nassim Taleb and I were lecturing in Mexico City at the weekend (thanks, RiskMathics!). In our free time we visited Teotichucan with its two impressive pyramids. The larger (Pyramide del Sol) is the third largest pyramid in the world by volume. The two pyramids and the surrounding temples, buildings, arenas, etc. were constructed about two thousand years ago and took two hundred years to complete.
Pyramide del Sol
The people of Teotichucan were divided into three castes. The lowest being the farmers, the middle being the builders (15,000 involved in the construction of pyramids and temples), and the highest being the priests and the applied mathematicians. Yes, our guide really did specify that they were applied mathematicians!
A priest and an applied mathematician.