Workers digging a well outside the city of Xi'an, China, in 1974 struck upon one of the greatest archaeological discoveries in the world: a life-size clay soldier poised for battle. 
 
 The diggers notified Chinese authorities, who dispatched government archaeologists to the site. 
 
 They found not one, but thousands of clay soldiers, each with unique facial expressions and positioned according to rank. And though largely gray today, patches of paint hint at once brightly colored clothes. Further excavations have revealed swords, arrow tips, and other weapons, many in pristine condition. 
 
 The soldiers are in trenchlike, underground corridors. In some of the corridors, clay horses are aligned four abreast; behind them are wooden chariots. 
 
 The terra-cotta army, as it is known, is part of an elaborate mausoleum created to accompany the first emperor of China into the afterlife, according to archaeologists. 
 
 China's Terra-Cotta Warriors 
 
 Young Emperor 
 
 Ying Zheng took the throne in 246 B.C. at the age of 13. By 221 B.C. he had unified a collection of warring kingdoms and took the name of Qin Shi Huang Di—the First Emperor of Qin. 
 
 During his rule, Qin standardized coins, weights, and measures; interlinked the states with canals and roads; and is credited for building the first version of the Great Wall. 
 
 According to writings of court historian Siam Qian during the following Han dynasty, Qin ordered the mausoleum's construction shortly after taking the throne. More than 700,000 laborers worked on the project, which was halted in 209 B.C. amid uprisings a year after Qin's death. 
 
 To date, four pits have been partially excavated. Three are filled with the terra-cotta soldiers, horse-drawn chariots, and weapons. The fourth pit is empty, a testament to the original unfinished construction. 
 
 Archaeologists estimate the pits may contain as many as 8,000 figures, but the total may never be known. 
 
 Unexcavated Tomb 
 
 Qin's tomb itself remains unexcavated, though Siam Qian's writings suggest even greater treasures. 
 
 "The tomb was filled with models of palaces, pavilions and offices as well as fine vessels, precious stones and rarities," reads a translation of the text. 
 
 The account indicates the tomb contains replicas of the area's rivers and streams made with mercury flowing to the sea through hills and mountains of bronze. Precious stones such as pearls are said to represent the sun, moon, and other stars. 
 
 Modern tests on the tomb mound have revealed unusually high concentrations of mercury, lending credence to at least some of the historical account. 
 
 Chinese archaeologists are also using remote-sensing technology to probe the tomb mound. The technique recently revealed an underground chamber with four stairlike walls. An archaeologist working on the site told the Chinese press that the chamber may have been built for the soul of the emperor. 
 
 Experimental pits dug around the tomb have revealed dancers, musicians, and acrobats full of life and caught in mid-performance, a sharp contrast to the military poses of the famous terra-cotta soldiers. 
 
 But further excavations of the tomb itself are on hold, at least for now. ||||| FILE - In this July 30, 2013 file photo, visitors walk past a display of the unearthed Terra Cotta Warriors cast by sunlight at the excavation site inside the No.1 pit of the Museum of Qin Terracotta... (Associated Press) 
 
 BEIJING (AP) — China is expanding the ranks of the famed Terra Cotta Warrior army with new excavations expected to yield hundreds more of the ancient life-size figures. 
 
 The museum overseeing the vast mausoleum of China's first emperor says it began work March 30 on the tomb's No. 2 pit that is smaller in scale but believed to be richer in archaeological value than the already excavated No. 1 pit. 
 
 Along with 1,400 warrior and horse statues, the pit is believed to contain 89 war chariots and 116 mounted soldiers, offering invaluable insights into the military culture of the Qin dynasty, the museum said in a statement on its website. 
 
 "The No. 2 pit contains the true essence of the Terra Cotta army," the museum's former curator was quoted as saying. 
 
 Discovered in 1974, the army is one of China's biggest tourist draws, attracting hundreds of thousands of visitors each year. In recent years, the warriors have joined the giant panda as a tool of Chinese "soft power," with several batches being exhibited overseas to enthusiastic crowds. 
 
 The army was built to guard the tomb of the first Qin emperor, Qin Shi Huang, who died in 210 A.D. after conquering much of what is now modern China. 
 
 In all, the tomb's three pits are thought to hold more than 8,000 figures of archers, infantry soldiers, mounted cavalry, horse-drawn chariots, officers, acrobats, musicians and others. 
 
 The pits is adjacent to the emperor's sprawling mausoleum that lies under a 76-meter (250-foot) mound and remains un-excavated as experts debate the pros and cons of doing so. 
 
 Ancient accounts tell of a huge complex of chambers, including underground rivers filled with flowing mercury, along with the remains of craftsmen and imperial concubines sealed alive in the tomb with the dead emperor. 
 
 The Terra Cotta statues weigh about 180 kilograms (400 pounds) each and range in height up to 183-195 centimeters (6 feet to 6 feet 5 inches) depending on rank. Generals are the tallest. 
 
 Originally brightly painted, they are intricately detailed with armor, top knots, weapons and boots. No two figures are alike, and craftsmen are believed to have modeled them after a real army. 
 
 A ruthless figure of fear and awe in Chinese history, Qin built an extensive system of roads and canals along with an early incarnation of the Great Wall of China while unifying measurements and establishing a single written language, currency and legal statutes. ||||| An archaeologist works on an excavation site of terracotta warriors in Xi’an April 30, 2015.[Photo/Xinhua] 
 
 XI'AN - China launched a second excavation project on Thursday on a burial pit in the ancient capital of Xi'an, where an army of terracotta warriors guards the mausoleum of China's first emperor. 
 
 Archaeologists plan to excavate about 200 square meters of Pit No.2, located near the tomb of Emperor Qinshihuang, founder of the Qin Dynasty (221-206 BC), according to Emperor Qinshihuang's Mausoleum Site Museum. 
 
 Archaeologist Yuan Zhongyi estimated that the burial pit has 1,400 clay figures and horses and 89 chariots waiting to be unearthed. 
 
 Yuan described Pit No.2 as "the essence of the terracotta warriors," for its mix of terracotta chariots, cavalry and archers. 
 
 "You can find all the kneeling archers, soldiers and cavalry in the No.2 pit," Yuan said. "Their colorful paint is also relatively well preserved." 
 
 The No.2 pit was famed for the unearthing of several colorful warriors, including a rare specimen with a green face, indicating that the army was once painted various colors that faded throughout the ages. 
 
 Located in Xi'an in northwest China's Shaanxi Province, the 56-square-km Mausoleum of Qinshihuang is the world's largest underground mausoleum. An army of more than 7,000 life-sized terracotta warriors and horses was discovered at the site in 1974. 
 
 First excavation began on Pit No.2 in 1994 and was halted in 2008 due to a lack of personnel and advanced protective technologies.
– A new excavation of something branded the "No. 2 pit" is a potentially much more remarkable undertaking than it sounds: It could swell the ranks of China's famed terracotta army. Work began March 30 on the pit, which sits adjacent to the tomb mound of Qin Shi Huang, an emperor who conquered much of modern China before his death in 210 BC. That pit has seen previous excavations, between 1994 and 2008, reports the Xinhua News Agency, and gave up statues whose coloring led archaeologists to conclude the clay warriors were originally painted. What they expect a 2,150-square-foot section of the pit to give up now: as many as 1,400 warrior and horse statues, 89 war chariots, and 116 mounted soldiers, the AP reports by way of the Emperor Qinshihuang's Mausoleum Site Museum. Those warriors would add to the 7,000 that were found at the site—the world's biggest underground mausoleum—since 1974. The No. 2 pit is thought to be a more archaeologically interesting site than the already excavated No. 1, with archaeologist Yuan Zhongyi describing the No. 2 as holding "the true essence of the terracotta army," noting the "colorful paint is also relatively well preserved." National Geographic's file on the terracotta warriors reports there are four pits that have seen some excavation, including one that was found to be empty, "a testament to the original unfinished construction." Qin's tomb mound hasn't been touched, and it's unclear whether China will ever decide to disturb a space that ancient texts describe as one filled with treasures. Last year saw one mystery of the terracotta army solved.