It has been concluded that its correct etymology is Chicnauhtecatl meaning "Lord of Nine", probably referring to the various deep lakes at the top of the cone.

[6] It is believed that Nevado de Toluca may once have been as tall as Popocatépetl, until an enormous eruption nearly 25,000 years ago blasted the top of the cone off and reduced its height by as much as 900 m (3,000 ft).

An eruption approximately 500 years later deposited layers of pumice on the mountain's east and northeast slopes.

Distal lahar deposits derived from the Upper Toluca Pumice event incorporated mammoth bones and other mammals in the basin of Mexico.

The winter season covers from November to April and precipitation is low, averaging 7.5 millimetres (0.5 in) in March, the driest month.

Bernardino de Sahagún wrote about the lakes as a place where the indigenous held ceremonies and sacrifices.

These deposits can be found all over the lakebed as the burning copal was set adrift on the lakes’ waters until it sank.

One of the sites is called Xicotepec which is at the top of a rocky dome known as the Cerro de Ombligo (Spanish for "the navel").

[9] There have been intermittent archeological excavations here with the most recent occurring in 2010 sponsored by INAH which found artifacts dating from the Epi-Classic (650-900 AD) and Post-Classic (900-1200 AD) periods and showed that the crater was a meeting place for astronomer priests to predict the growing season.