Passage: In 1894 the United States Consul to Yucatán, Edward Herbert Thompson, purchased the Hacienda Chichén, which included the ruins of Chichen Itza. For 30 years, Thompson explored the ancient city. His discoveries included the earliest dated carving upon a lintel in the Temple of the Initial Series and the excavation of several graves in the Osario (High Priest's Temple). Thompson is most famous for dredging the Cenote Sagrado (Sacred Cenote) from 1904 to 1910, where he recovered artifacts of gold, copper and carved jade, as well as the first-ever examples of what were believed to be pre-Columbian Maya cloth and wooden weapons. Thompson shipped the bulk of the artifacts to the Peabody Museum at Harvard University.

Question: Which ancient city was explored by Thompson?
Chichen Itza