El Caracol, the ancient observatory (Mexico) online puzzle
El Caracol is an ancient astronomical observatory located in the pre-Columbian city of Chichén Itzá, built by the Maya civilization. The name of that structure comes from Spanish and mean “a snail”, referring to the spiral shape of stairs leading towards the top of the observatory. The structure was erected in the 10th century in order to observe the sky at night. It is possible to see the whole firmament from the top of the structure as it is not obscured by any other buildings nor trees of the lush woods that the Yucatan peninsula is overgrown with. Despite the lack of advanced technology, the Maya people were great astronomers. Their naked-eye observations were accurate enough to predict the solar or lunar eclipses, describe the movement of planets of the Solar System and create very precise calendars.