In 1986, divers stumbled upon a nearly 2,000-year-old Roman shipwreck some six miles off the coast of the town of Grado, Italy. Measuring 55 feet long and 16 feet wide, the small trade vessel was stocked with 600 amphorae, or vases, packed with sardines and other fish. Further study of the shipwreck revealed that the ancient Roman engineers also had built in a hydraulic system that allowed the ship to carry an aquarium with live fish. 
 
 Over the years, metal detector enthusiasts, particularly those in the United Kingdom, have uncovered archaeological treasures buried beneath the Earth. In 2009, 30-year-old Nick Davies hauled in 10,000 ancient Roman coins that he had found inside a clay pot buried in Shropshire, U.K. That same year, a trove of 1,500 gold and silver pieces dating back to the Dark Ages were found on a farmer's field in the western region of Staffordshire, England. Last year, 63-year-old David Crisp uncovered 52,000 ancient Roman coins, later given a value of around $1 million, in a clay pot in southwestern England. 
 
 In 1991, German tourists stumbled upon a frozen body in a glacier on the Ötztal Alps between Italy and Austria. Although they originally thought the corpse to be the result of a recent death, the iceman mummy, named Ötzi, in fact dated back 5,300 years. Since Ötzi's discovery, the mummy has been extensively studied. Scientists have learned everything from his last meal to his cause of death to his possible occupation and they have even made reconstructions of his face. Ötzi died in the spring as a result of an arrowhead striking his left clavicle artery. He likely received a ceremonial burial and was found beside tools and other personal items. 
 
 In case you don't know what a geoglyph is, ancient Peruvians went through the trouble of leaving a picture-perfect definition. Known as the Nazca Lines, these giant carvings into the Earth were only discovered by airplane in the 1930s. Located in the Nazva desert in southern Peru around 250 miles (400 kilometers) south of Lima, the geoglyphs resemble a number of animals including a spider (as seen here), a condor, a monkey, a tree, as well as human figures and geometric patterns. Why exactly indigenous tribes living in the area between 100 B.C. and 650 A.D. felt compelled to produce these works remains a mystery, though archaeologists agree that it is likely tied to religious customs. 
 
 As Napoleon Bonaparte's army marched through north Africa during his campaign in Egypt, they stumbled upon what would become known as the Rosetta Stone, after the town where it was discovered. Within Bonaparte's army was a squadron of scholars called Institute of Egypt, also known as the Scientific and Artistic Commission. As the military settled around the Nile Delta, the Institute explored local ruins and artifacts. After the discovery of the stone in 1799, several copies of the inscriptions on its face were made, since no one could read them at the time. By 1802, the Greek and Demotic portions of the stone had been deciphered by scholars. The hieroglyphics posed a different challenge all together, however, and it would take 20 years before French scholar Jean-François Champollion announced that he had cracked the code. By deciphering the hieroglyphs, Champollion opened a whole new door to understanding the civilization of ancient Egypt. The Rosetta Stone is currently kept in the British Museum. 
 
 The Dead Sea Scrolls are a collection of over 800 biblical texts made of animal skin and papyrus. Dating to around 2,000 years ago, between the years 200 B.C. and 70 A.D., the scrolls could well be the oldest such documents in existence and have deepened historians' understanding of religious history. These documents may have been lost to history had a Bedouin shepherd named Muhammed edh-Dhib and his cousin not stumbled upon the first manuscripts along the northern shore of the Dead Sea at a remote site known as Qumran in 1947. The last fragments of the Dead Sea Scrolls collection was uncovered in the mid-1950s. Although the scrolls have been extensively studied and translated, one big mystery remains: Who exactly wrote them? 
 
 On Sept. 12, 1940, four teenagers followed their wayward dog into a cave complex near the village of Montignac in southwestern France. To their surprise, the caves hosted something remarkable: nearly 2,000 paintings and etchings of animals, humans and abstract shapes on the walls dating back between 15,000 and 25,000 years. Known as the Lascaux caves, the complex features figures depicted in surprising detail given the age of the illustrations. Animals portrayed on the cave walls included horses, stags, bison and felines. Archaeologists believed the caves were used for ritualistic purposes. Some parts of the illustrations even appear to construct a narrative, but what they mean exactly has yet to be deciphered. The caves were open to the public in 1948, but closed in 1963 in order to preserve the site from damage. 
 
 In the search for buried history, archaeologists pour their resources into uncovering the remnants of the distant past. With know-how, persistence and a little luck, archaeologists can push aside dirt and rock and find an artifact of historical significance. Although chance plays a big role in unearthing history, archaeological treasures have been stumbled upon purely by accident, often by those outside the scientific community. In these photos, explore several particularly serendipitous finds of unique artifacts, some of which reach as far back as prehistory. 
 
 Workers building a sewer line in Jerusalem unearthed a section of the ancient lower aqueduct, which had long been one of the city’s principal sources of water. 
 
 Constructed by the Hasmonean kings more than 2,000 years ago to provide clean water to Jerusalem, the aqueduct was part of an elaborate water supply system devised for a city that had experienced a number of droughts. 
 
 The water conduit functioned intermittently until about 100 years ago, when it was replaced by a modern electrically operated system. 
 
 Video: Ancient Roman Aqueduct Source Discovered 
 
 Unearthed in Umm Tuba, an Arab neighborhood in East Jerusalem, the aqueduct begins at the Eitam spring near Solomon’s Pools, three reservoirs south of Bethlehem that are the heart of the water system, and is approximately 13 miles long. 
 
 “Despite its length, it flows along a very gentle downward slope whereby the water level falls just one meter (3.2 feet) per kilometer of distance (0.62 miles),” Ya’akov Billig, the excavation director, said. 
 
 “At first, the water was conveyed inside an open channel and about 500 years ago, during the Ottoman period, a terracotta pipe was installed inside the channel in order to better protect the water,” he added. 
 
 Medieval Aqueduct Found in Jerusalem 
 
 The aqueduct tunneled beneath the town of Bethlehem, ran through a number of neighborhoods in Jerusalem and finally entered the Temple Mound over Wilson’s Arch bridge. 
 
 The Umm Tuba section of the aqueduct has now being covered up again “for the sake of future generations,” the Israel Antiquities Authority (IAA) said. 
 
 The archaeologists are now working to expose sections of its remains and make them soon accessible to the general public. ||||| A section of Jerusalem’s Lower Aqueduct, which brought water to Jerusalem more than two millennia ago, was uncovered in the East Jerusalem neighborhood of Umm Tuba during the construction of a new sewer line, it was announced Thursday. 
 
 The ancient aqueduct was discovered during digging last month by the Gihon Water Company, which was laying new pipes to modernize the sewer system in the Umm Tuba and Sur Baher neighborhoods in East Jerusalem. 
 
 The Israel Antiquities Authority excavated the area after the aqueduct was found. 
 
 “The Lower Aqueduct to Jerusalem, which the Hasmonean kings constructed more than 2,000 years ago in order to provide water to Jerusalem, operated intermittently until about one hundred years ago,” said Ya’akov Billig, the director of the excavation. 
 
 According to Billig, the aqueduct begins at the Ein Eitam spring near Solomon’s Pools south of Bethlehem and stretches 21 kilometers to Jerusalem. “Despite its length, it flows along a very gentle downward slope whereby the water level falls just one meter per kilometer of distance. At first, the water was conveyed inside an open channel, and about 500 years ago, during the Ottoman period, a terra cotta pipe was installed inside the channel in order to better protect the water.” 
 
 Billig added that while the aqueduct’s route went through uninhabited areas when it was first built, it now runs through several populated areas, including Umm Tuba, East Talpiot and Abu Tor, due to Jerusalem’s expansion. 
 
 Since the ancient aqueduct was one of Jerusalem’s most important water sources, the city’s rulers carefully preserved it until an electrically operated water system replaced it roughly a century ago. Now that its importance is mainly historical, Billig said, the Israel Antiquities Authority is taking steps to preserve parts of the aqueduct, study them and make them accessible to the public. 
 
 The sections of the aqueduct in Umm Tuba were covered up once more after the Antiquities Authority’s study, but other sections are accessible to the public in other areas in Jerusalem, such as the water tunnel in Armon Hanatziv and near the Sultan’s Pool. ||||| Part of an ancient aqueduct built more than 2,000 years ago to transport water into the city of Jerusalem was uncovered during a recent construction project, according to the Israel Antiquities Authority. 
 
 A section of the so-called Lower Aqueduct was discovered in the modern-day neighborhood of Umm Tuba, in East Jerusalem, during efforts to construct a new sewer line. The Lower Aqueduct was originally built more than 2,000 years ago by kings in the Hasmonean dynasty, who ruled Judea and its surrounding regions from about 140 B.C. to 37 B.C., and preceded King Herod the Great. 
 
 The sprawling, 13-mile-long (21 kilometers) aqueduct carried water to the capital, and "operated intermittently until about 100 years ago," Ya'akov Billig, director of the aqueduct excavation with the Israel Antiquities Authority (IAA), said in a statement. [The Holy Land: 7 Amazing Archaeological Finds] 
 
 The Lower Aqueduct fed from the En Eitam spring, which is located near three ancient reservoirs known as Solomon's Pools that are about 3 miles (5 km) southwest of Bethlehem. As water passed through the channel, it flowed down a gentle slope to Jerusalem, passing through the modern-day neighborhoods of Umm Tuba, Sur Bahar, East Talpiot and Abu Tor, according to the IAA. 
 
 "At first, the water was conveyed inside an open channel, and about 500 years ago, during the Ottoman period, a terra cotta pipe was installed inside the channel in order to better protect the water," Billig said. 
 
 For nearly 2,000 years, the Lower Aqueduct remained one of Jerusalem's principal sources of water, IAA officials said, which is why city rulers kept the structure so well preserved. About 100 years ago, the channel was replaced by an electrically operated water-distribution system. 
 
 The Umm Tuba section of the aqueduct was uncovered by workers at Gihon Company Ltd., who are constructing the new sewer line. Archaeologists at the IAA conducted an excavation of the site following its discovery, but the remains have since been covered up again to preserve the structure and prevent any damage, agency officials said. 
 
 Other sections of the extensive aqueduct have been uncovered in the past, including in the Armon Ha-Natziv tunnels in the City of David, on the Sherover promenade in southern Jerusalem and around the Sultan's Pool along the west side of Mount Zion in Jerusalem, IAA officials said. 
 
 Follow Denise Chow on Twitter @denisechow. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.
– Workers constructing a sewer line in East Jerusalem last month discovered a 2,000-year-old water-supply system that—think about this—worked fairly well until the last century, LiveScience reports. The 13-mile long Lower Aqueduct, which was fed by a spring south of Bethlehem and runs through four modern-day Jerusalem neighborhoods, was built by kings governing Judea and environs from roughly 140 BC to 37 BC. City rulers kept it up over the years, covering the open channel with terra cotta pipe about 500 years ago. It remained a major water-supply source until an electrical water distribution system replaced it roughly 100 years ago, according to the Israel Antiquities Authority. The IAA says it will cover part of the aqueduct "for the sake of future generations" and expose parts for access by the general public, Discovery reports. Meanwhile, archaeologists are marveling: "The aqueduct begins at the ‘En ‘Eitam spring, near Solomon’s Pools south of Bethlehem," says IAA Director Ya'akov Billig. "Despite its length, it flows along a very gentle downward slope whereby the water level falls just one meter per kilometer of distance." The original designers look pretty smart, too, having built the aqueduct in uninhabited areas where Jerusalem neighborhoods now exist, the Times of Israel notes. Other parts of the aqueduct system have been found before, including tunnels in the City of David and ones near the Sultan's Pool beside Mount Zion in Jerusalem.