The tiny brick tower is a museum dedicated to the art of photography. The whole place breathes of history.
Wikipedia http://en.wikipedia.org/wiki/Cuernavaca#El_Castillito
Address 3-A Calle Profesor Agustín Guemes Celis, Cuernavaca 62000, Mexico
Coordinates 18°55'44.413" N -99°14'17.303" E