Archaeologists make great efforts to find sites. But many sites are discovered by accident – including some of the most famous ones. For example, farmers in Shaanxi province who were digging a well unearthed (挖出) the 2,000-year-old Terracotta Warriors. Utility workers found Templo Mayor, the Great Temple of the Aztec Empire, right under the streets of Mexico City. Construction workers (建筑工人) often run into ancient remains. Archaeologists are often invited to construction sites to do surveys before construction starts.