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, and Northern El Salvador to as far north as central Mexico, more than  from the Maya area. Many outside influences are found in Maya art and architecture, which are thought to have resulted from trade and cultural exchange rather than direct external conquest.