The city covered eight square miles; 80 to 90 percent of the total population of the valley resided in Teotihuacan. Apart from the pyramids, Teotihuacan is also anthropologically significant for its complex, multi-family residential compounds, the Avenue of the Dead, and its vibrant, well-preserved murals. Additionally, Teotihuacan exported fine obsidian tools that are found throughout Mesoamerica. The city is thought to have been established around 100 BCE, with major monuments continuously under construction until about 250 CE. The city may have lasted until sometime between the 7th and 8th centuries CE, but its major monuments were sacked and systematically burned around 550 CE.