One of the most important advancements developed by the Mayans was written language. The Mayans developed a complex system of writing, which consisted of both an alphabet, as well as symbols, which represented whole words or thoughts.
These writings were recorded in books made out of bark and plaster, as well as carved into monuments, bones and stone. Many of these writings have survived to the present, and help give us an accurate look at the Mayan's history and culture.
In the old days, when things got rough, what you did was without.
The Mesopotamians were the first people to keep records of lunar eclipses, beginning in 2200 B.C.