In the town of Almoloya de Juárez in the State of Mexico, there is a small church from the 16th century in whose courtyard there is a rectangular basin where flows a spring. This basin is full of fish, silent witnesses of the "mystery" of the "Almoloya Streak", a phenomenon no one has been able to explain. This optic effect -mobile line or streak- is caused by a division of the water surface in two different density zones, the first, completely clean, the second, full of dust particles, leaves and slime. A few kilometers distant and next to the village of Tecaxic, there is another point of interest: Calixtlahuaca (Pre-hispanic ruins), a religious fort dedicated to Ehecatl-Quetzalcoatl. It is precisely at the foot of this temple that the famous sculpture of Ehécatl (a man carrying a mask in the shape of a pointed beak), was found - one of the outstanding pieces displayed at the National Museum of Anthropology and History in Mexico City.