The influence of indigenous populations such as the original Mayan and Aztec civilizations would most likely to be seen in the works of

I would say that the Mayan and Aztec civilizations influence would be especially in the architecture of their buildings and pyramids. The Mayans had well laid out stone complexes complete with temples, ball courts and had carved stelae or mythical figures in the complexes. The Aztecs had pyramids also, like the Temples of the Sun and Moon at Tenochtitlan near Mexico laid out according to their astronomical observations.