The tropical alpine lake El Sol, which fills the bottom of the crater in Nevado de Toluca, is situated at an altitude of 2 500 m above sea level. Its very clear water allow the solar radiation reach the bottom, which is in between 6 and 14 m deep.
The El Sol is en endorrheic lake, meaning, there is no connection to a river or a stream. The lake is roughly oval in shape and has a surface of 24 ha.