The term 'Mexican Pyramid Builder' refers to two ancient civilizations, the Aztecs and the Maya. The Aztecs were a Mesoamerican civilization that flourished in central Mexico in the 14th to 16th centuries. They built many impressive pyramids, such as the Great Pyramid of Tenochtitlan. The Maya were another Mesoamerican civilization that flourished in southern Mexico and northern Central America from the 4th century BC to the 16th century AD. They also constructed many impressive pyramids, such as the Temple of Kukulkan at Chichen Itza. Both the Aztecs and the Maya were renowned for their skill in constructing monumental pyramids.