The Maya is a Mesoamerican civilization, noted for the only known fully developed written language of the pre-Columbian Americas, as well as its art, architecture, and mathematical and astronomical systems.The Maya civilization shares many features with other Mesoamerican civilizations due to the high degree of interaction and cultural diffusion that characterized the region. Advances such as writing, epigraphy, and the calendar did not originate with the Maya; however, their civilization fully developed them. Maya influence can be detected from Honduras, Guatemala, El Salvador and to as far as central Mexico, more than 1000 km (625 miles) from the Maya area.http://en.wikipedia.org/wiki/Mayan_civilisation. In common with the other Mesoamerican civilizations, the Maya used a base 20 (vigesimal) and base 5 numbering system (see Maya numerals). Also, the preclassic Maya and their neighbors independently developed the concept of zero by 36 BC.Inscriptions show them on occasion working with sums up to the hundreds of millions and dates so large it would take several lines just to represent it. They produced extremely accurate astronomical observations; their charts of the movements of the moon and planets are equal or superior to those of any other civilization working from naked eye observation.[citation needed]