In 1849, an explorer named Austin Henry Layard excavated ruins in northern Iraq and uncovered a library that had been buried for about 2,500 years. The collection belonged to an ancient Assyrian king, Ashurbanipal, and contained tens of thousands of clay tablets written in several languages, including Sumerian, a language that had already been ancient by the king’s lifetime. It took linguists more than 30 years to begin deciphering the texts.
The Sumerians, who lived in southern Iraq between the Tigris and Euphrates rivers, built some of the world’s first cities, including Uruk, Eridu, Ur, and Lagash. Uruk had a population of around 40,000 people by 3200 to 3100 BCE, making it the largest city on Earth at the time. They developed the first writing system, organized agriculture, and established complex urban societies. Then, for reasons that remain unclear, their civilization declined and was largely forgotten for nearly 2,000 years.
In their own writings, the Sumerians described beings they called the Anunnaki, a term some researchers translate as “those who came down from the sky.” Rather than describing them through myths and legends, the Sumerians wrote about these beings almost like administrators, with names, ranks, and records of disputes among them. Mainstream historians consider the Anunnaki to be deities invented in the same way other ancient cultures created their gods, but the unusually practical tone of the records has led to alternative interpretations.
One damaged tablet describes 11 points in the sky that correspond to specific astronomical positions, with a 12th point that is unreadable. According to the surviving text, when that final point is reached, a barrier above the world will open, and the beings will return. The tablet also mentions the “me,” a Sumerian concept referring to the powers and knowledge that make civilization function. The damaged section seems to say these could be given back, changed, or taken away when the barrier opens. The 11th point reportedly aligns with a rare alignment of Jupiter, Saturn, and the moon expected sometime this century, but the damaged 12th point prevents a precise date from being determined.
The Sumerians measured long cycles of time using a unit called a “sar,” equal to 3,600 years. The Sumerian King List, a document written on clay tablets, describes early kings ruling for a combined 241,200 years before a great flood, which equals exactly 67 sars. Mainstream historians view these pre-flood reign lengths as symbolic, while other theories suggest they may relate to a hypothetical object called Nibiru, described as following a long orbit that brings it near Earth every few thousand years. There is no astronomical evidence that such an object exists.
In 1872, a translator named George Smith was working through tablets at the British Museum when he found a description of a massive flood. The story described deities sending a flood to wipe out humanity, with one man chosen to survive by building a large boat, loading animals aboard two by two, and releasing a bird to find dry land. The account was written down at least 1,000 years before the same story appeared in the book of Genesis.
Archaeological work at Eridu, one of the oldest Sumerian cities, has provided extensive information about its development. The city was founded around 5,400 BCE and was considered sacred as the home of the god Enki. Excavations uncovered a step pyramid and layers of temple rebuilds spanning more than 2,000 years, with each new version larger than the last. Recent mapping using satellite images, drones, and soil analysis found more than 4,200 canals that brought water from the Euphrates River to about 700 farms. The city thrived as a religious and trade center before being abandoned around 600 BCE, likely after the Euphrates changed course.
In a related discovery, archaeologists found administrative tablets in another Sumerian city that provide the first clear evidence of how the Akkadian Empire, the world’s first known empire, operated. The tablets record deliveries, spending, inventory, and population data, showing that women held powerful positions and that the empire had serious organizational planning.
Research into Ice Age artifacts has also changed the understanding of early human intelligence. About 40,000 years ago, people carved patterns of crosses, dots, and lines into bone and ivory objects found across Europe. A computational study of more than 3,000 symbols on around 260 artifacts found that these carvings contain information density comparable to the earliest writing system from Mesopotamia. The researchers concluded that Ice Age humans spent tens of thousands of years developing symbolic encoding systems before true writing emerged, rather than inventing it suddenly 5,000 years ago.
At Olduvai Gorge in Tanzania, researchers found 27 bone tools made from elephant and hippo limb bones dating back about 1.5 million years. The toolmakers shaped them using knapping, a technique also used for stone tools, which requires understanding how the material will fracture. The creators, likely Homo erectus, preferred thick limb bones, indicating knowledge of anatomy and material strength.
The Antikythera mechanism, discovered by sponge divers off the Greek island of Antikythera in 1901, is a bronze device with gears and wheels that calculated astronomical positions and tracked athletic game cycles. X-ray scans revealed an instrument far more complex than initially assumed. The device dates to about 2,000 years ago, and its sophistication has led scientists to acknowledge gaps in their understanding of ancient Greek engineering.
In 1929, scholars in Turkey discovered a map drawn on gazelle skin by Ottoman admiral Piri Reis in 1513. It depicted Europe, North Africa, the coast of Brazil, and several islands, and included information from a map drawn by Columbus during his third voyage that is otherwise lost. The map also showed Antarctica, which had not yet been discovered, leading to questions about its depiction of the continent’s topography.
Stone spheres found in Costa Rica, known as bolas de piedra, vary from tennis-ball size to seven feet in diameter, with the largest weighing 16 tons. They were made from granodiorite, a hard rock similar to granite. Archaeologists confirm they are human-made but still do not know their purpose, though theories include solar system representations or markers of social status.
An artifact found in Iraq in 1936 consists of a ceramic pot, a copper cylinder, and an iron rod sealed with asphalt. Some researchers suggested it could have generated an electric charge when filled with an acidic or alkaline liquid, leading to comparisons with a battery. The hypothesis was proposed by Austrian archaeologist Wilhelm König but has been disputed, and the artifact’s origin and purpose remain unclear.
Göbekli Tepe in southeastern Turkey, discovered in 1994, is a ceremonial complex of massive stone pillars dating to around 12,000 years ago, making it older than the Egyptian pyramids by more than 7,000 years. The site predates the end of the Ice Age and challenges the assumption that farming preceded complex social organization. One pillar contains 365 V-shaped carvings that some researchers interpret as a solar calendar. Other carvings depict dangerous animals including foxes, lions, and scorpions, which may represent constellations. The Vulture Stone, one of the most complex pillars, has been interpreted as possibly recording a comet impact that occurred around 10,850 BCE, an event associated with a period of sudden cooling called the Younger Dryas. Nearby sites, including one called Karahan Tepe, may be even older.
The Maya civilization developed a calendar system using interlocking cycles, including a 365-day solar year and a 260-day sacred calendar. Inscriptions on monuments also referenced an 819-day count, which researchers could not initially explain. In 2023, a study proposed that the 819-day count was not a literal calendar but a building block for a larger system of 20 periods. This expanded framework aligned with the synodic periods of the visible planets, including Mercury, Venus, Mars, Jupiter, and Saturn. The Maya tracked planetary movements with naked-eye observation and incorporated astronomical alignments into their architecture.
Recent DNA analysis of the sarsen stones at Stonehenge determined they came from West Woods, about 15 miles from the site. The smaller blue stones likely came from the Preseli Hills in southwest Wales, about 150 miles away. Radiocarbon dating shows the monument was built in phases starting around 3,100 BCE. Various theories have been proposed for its purpose, including as a solar calendar, healing center, or gathering place.
In Dorset, a site called Flagstones has been confirmed as the earliest large circular monument in Britain, dating to around 3,200 BCE, about 200 years older than the earliest stages of Stonehenge. The site consists of a circular ditch with pits containing the remains of at least seven people. The discovery of a similar monument near Stonehenge called Lark Hill suggests the landscape was already significant before the famous stones were erected.
Research published in 2018 found that the altar stone at Stonehenge came from the Orcadian Basin in northeastern Scotland, more than 400 miles away. This has led to theories that Stonehenge may have been built as an effort to unite different groups across Britain during a period of population change. The altar stone aligns with the setting sun during the winter solstice, carrying possible ancestral meaning for its builders.
Several notable archaeological hoaxes have been exposed over the years. The Piltdown Man, presented in 1912 as a missing link between apes and humans, was revealed in 1949 to be a human skull combined with an orangutan jaw, with filed teeth and stained bones. A gold tiara purchased by the Louvre in the late 19th century was identified by the goldsmith who made it as a modern piece. The Cardiff Giant, a ten-foot-tall figure carved from gypsum and buried in 1869, drew paying crowds even after being exposed as a hoax. Crystal skulls displayed in museums were found to have been made with modern rotary tools. The Vinland Map, claimed to show Viking exploration of America, was confirmed in 2021 as a modern forgery. A fossil called Archaeoraptor, presented by National Geographic in 1999 as a link between dinosaurs and birds, was found to be assembled from different species. In 2020, the Museum of the Bible acknowledged that all 16 fragments of its Dead Sea Scroll collection were modern forgeries. A mummy presented in 2000 as a Persian princess turned out to be a modern woman whose remains had been altered and sold as a fake relic.
Recent technology has also revealed large-scale ancient engineering projects. More than a dozen pits surrounding Durrington Walls, a Neolithic settlement near Stonehenge, form a circle more than a mile wide. Dating to around 2500 BCE, the pits measure about 30 feet across and 15 feet deep. Soil analysis confirmed they were human-made. In the Amazon rainforest, LIDAR scanning identified traces of 2,500-year-old cities with more than 6,000 rectangular earth platforms, agricultural terraces, drainage systems, and straight roads crossing at right angles. In Peru, researchers used artificial intelligence to identify 303 previously unknown Nazca geoglyphs in about six months, nearly doubling the number of known figures.
