Glyn,
The Mayans were extremely advanced in their measurement of planetary phenomena and the cyclical nature of the universe.
This seems to be true for several very old civilizations. In fact based on some of the things they are now finding, I sometimes wonder if we are the remains of the real intelligent civilizations that once inhabited this planet and they have long since departed to other planets. Just look at all of the things we now have that are basically just improved versions of things they had long ago. The Egyptians were very advanced. And look at what the Greeks gave us.
Ron