 The Cascajal Block was discovered by road builders in the late 1990s in a pile of debris in the village of Lomas de Tacamichapan in the Veracruz lowlands in the ancient Olmec heartland of coastal southeastern Mexico.The block was found amidst ceramic shards and clay figurines and from these the block is dated to the Olmec archaeological culture's San Lorenzo Tenochtitlán phase, which ended c. 900 BCE, preceding the oldest Zapotec writing dated to about 500 BCE.Archaeologists Carmen Rodriguez and Ponciano Ortiz of the National Institute of Anthropology and History of Mexico examined and registered it with government historical authorities.