National Geographic : 1990 Mar
PLEIADES A lava-tube cave with four lobes, suggesting the quarters of the universe, was discovered in 1971 under the Pyramid of the Sun. The chamber probably dictated the temple site and alignment, since, like many ancient peoples, the Teotihuacanos apparently believed caves were the places of emergence for their earliest ancestors. major source of the city's water. On this line they laid out their main avenue, now called the Street of the Dead, and on it built the Pyramid of the Moon, the photographer's vantage point. To illustratethe city's alignment, he held two fishlines lighted by a red strobe before his lens. One line sights due south over the Pyramid of the Sun to pyramid-shaped Cerro Patlachique. The other, along the Street of the Dead, is 151/2 degrees west of south, the basic alignment of the city. Two so-called pecked crosses-one in a plaster floor southwest of the Pyramid of the Sun (below), the other on Cerro Colorado-may have served as surveyor's markers for the strict grid, which was maintained even to suburban barrios. Teotihuacan eventually expanded to eight square miles, an area larger than imperial Rome, before being abandoned aboutA.D. 750. But its influence had already spread. Some 70 known pecked crosses, possibly used in ritual, occur in ruins from northern Mexico to Guatemala.Likewise, the skewed alignment is found in many Mesoamerican sites.