The Aztec religion is the Mesoamerican religion of the Aztecs. Like other Mesoamerican religions, it had elements of human sacrifice in connection with a large number of religious festivals which were held according to patterns of the Aztec calendar. It had a large and ever increasing pantheon; the Aztecs would often adopt deities of other geographic regions or peoples into their own religious practice. Aztec cosmology divided the world into upper and nether worlds, each associated with a specific set of deities and astronomical objects. Important in Aztec religion were the sun, moon and the planet Venus—all of which held different symbolic and religious meanings and were connected to deities and geographical places.