The El Caracol “observatory” stands as a monument not only to the architectural skill of the ancient Mayans but also to their surprisingly advanced understanding of the heavens. El Caracol, which means “snail” in Spanish is named after the winding staircase that rounds the interior of the central tower. Dating to around 906 AD, the crumbling viewing tower stands on a large square platform high above its surroundings. From the tower the Mayans could view the sky above the vegetation without any obstruction.
In particular, El Caracol seems to be carefully aligned with the motions of Venus. Venus had tremendous significance for the Maya. This bright planet was considered the sun’s twin and a war god. Mayan leaders used the changing position of Venus to plan appropriate times for battles and raids. The grand staircase that marks the front of El Caracol faces 27.5 degrees north of west, which is out of line with the other buildings at the site, but an almost perfect match for Venus’ most northerly position in the sky. Also, a diagonal formed by the northeast and southwest corners of the building aligns with both the summer solstice sunrise and the winter solstice sunset.