Ten archaeological mysteries, from Super-Henge to the 2,000-year-old computer

Dead Sea Scrolls that pinpoint buried treasure and the ancient tomb protected by the terracotta army are among some of the world’s most fascinating, enduring historical puzzles

The tomb of Emperor Qin Shi Huang, which China's famous terracotta army was created to protect, has never been excavated. Ancient documents claim it is home to an underground palace. EPA

Discovered on a Roman shipwreck, the 2,000-year-old "computer", the Antikythera Mechanism, was so advanced that it wasn't until the 14th century that anything remotely like it was engineered. EPA / CARDIFF UNIVERSITY

Scotland's Neolithic Cochno Stone, pictured in the 1930s, is covered in circles and swirling patterns that are thought to be art or astronomy-related. Similar patterns have been found across Northern Europe. University of Glasgow

Bronze Roman Dodecahedrons have been unearthed across Europe, yet no one knows what they are or what purpose they served. Getty

The Copper Scrolls (25-100BC), part of the Dead Sea Scrolls excavation, contain directions to hidden treasure that has never been found. Courtesy Jordan Museum

Gobekli Tepe in Turkey was built before the invention of the wheel. Its discovery changed the way historians viewed the evolution of civilisation. EPA-EFE

The Super-Henge in Wiltshire, the UK, was built more than 4,600 years ago. Consisting of 90 monoliths, each up to 4.5 metres tall, archaeologists do not know why it was created or why it was intentionally buried. Artist's impression © LBI ArchPro, Juan Torrejón Valdelomar, Joachim Brandtner

A stele from the lost, sunken Egyptian city of Thonis-Heracleion. The piece was believed to have been commissioned by Nectanebos I (378-362 BC). Christoph Gerigk / Franck Goddio / Hilti Foundation

Inhabited since 900 AD, the site of Sacsayhuaman in Cusco, Peru was built by the Incas using stones without mortar, but no one knows what it was created for. Getty

You don’t have to be Indiana Jones to appreciate a good archaeological enigma.

While some of the world’s historical phenomena have cemented themselves in the global consciousness, such as Peru’s Nazca Plains, or the lingering riddle that is Stonehenge, there are many lesser-known finds that continue to baffle experts.

From the “world’s first analogue computer” created more than 2,000 years ago and found on a Roman shipwreck, to a Turkish settlement that turned every theory of civilisation on its head, here are 10 incredible archaeological finds that continue to raise more questions than answers.

1. Qin Shi Huang’s tomb, China

While China's terracotta army has been excavated since its discovery in 1974, the tomb of Emperor Qin Shi Huang, which they were built to protect in the afterlife, has never been opened. EPA

While the 1974 discovery of the terracotta army by farmers in China’s Shaanxi province became one of the most fascinating archaeological finds of the 20th century, the tomb that the 8,000-plus strong army was protecting remains unexcavated almost 50 years after its discovery.

Emperor Qin Shi Huang (259BC – 210BC) is believed to be buried in a pyramid-shaped mausoleum north-east of his terracotta army.

But concerns about traps, high levels of mercury and preservation mean the tomb has never been opened.

Ancient writings appear to indicate that the tomb features an underground palace and a vast network of caves, all of which was built by more than 700,000 workers in three decades.

2. The Khatt Shebib, Jordan

The origins, construction and purpose of a 150-kilometre stone wall that runs across southern Jordan remains a mystery to archaeologists and scientists.

Starting in the north near Wadi Al Hasa and running south-east to Ras An Naqab, the wall passes mainly through the southern Jordan desert, with many side walls branching off.

It was believed to have been built by Bedouins.

The ruins were first brought to the world’s attention in 1948 by the British diplomat Sir Alec Kirkbride.

That prompted visits from archaeologists and scientists around the globe who remain divided on when the wall was built.

Estimates range from the Iron Age (about 1200BC) to the Nabataean period of the fourth to first centuries BC.

The purpose of the wall, which would have been about 1.5 metres tall, remains a mystery, with some believing it was used for agriculture and others as a border.

3. Antikythera Mechanism, Greece

On display at the National Archaeological Museum in Athens, the Antikythera Mechanism has been called the “world’s first analogue computer”, but experts remain unsure what it was used for.

Discovered in 1901 in the wreck of a 2,000-year-old Roman cargo ship off the coast of the Greek island of Antikythera, the bronze artefact is made of interlocking gears with indecipherable characters etched across the faces.

Experts cannot agree on when it was built, with estimates ranging between 87 and 204BC, and machines as complex as the mechanism did not reappear until more than 1,000 years later in the 14th century.

Why the highly sophisticated device was created is another enigma. Theories include that it was a navigational astrolabe, tracked stars and planets, predicted eclipses, and was used to track the four-year cycle of the early Olympiad.

4. The Cochno Stone, Scotland

The Neolithic Cochno Stone in Glasgow, Scotland is believed to date to between 4000 and 2000 BC. The hand-carved circles and swirls remain a mystery. Photo: University of Glasgow

The Cochno Stone — also known as the “Whitehill Stone” and the “Druid Stone” — was found in Glasgow in the mid-1800s.

Measuring 13 metres by 8 metres, it is covered in swirling patterns called “cup and ring marks”, the likes of which have been found at other prehistoric sites across northern England and Europe.

Archaeologists and anthropologists have debated the markings for years, with some believing they are astronomical while others think it is ancient artwork.

Rock art of this nature is believed to belong to the Neolithic period (4000 to 2000BC), but no one knows who drew them on the Cochno Stone or why.

Due to concerns over erosion and vandalism, the British government had the rock covered in 1965, and it was most recently uncovered for more excavation for three weeks in 2016.

5. Roman Dodecahedrons, worldwide

Made of bronze or stone and hollow in the middle, Roman Dodecahedrons have been found across Europe in Spain, France, Germany, Hungary, Wales and Italy.

The first recorded discovery was in 1739, but since then no one has been able to figure out what they are or what they were used for.

Ranging from four to 11 centimetres in size, they date to between 100 and 300 AD, but scholars have found no mention of them in Roman texts or painted imagery.

Theories concerning their use include as grain calendars, religious artefacts, toys, fortune-telling devices or objects connected with money, because many were discovered alongside coins.

6. The Copper Scroll, Jordan

One of the famous Dead Sea Scrolls, the Copper Scroll was discovered by archaeologists on March 14, 1952, near Khirbet Qumran. It was the last of 15 scrolls discovered in the cave.

While the text on the other scrolls, written on papyrus, were concerned with hymns, prayers and formulas, the Copper Scroll, estimated to date to between 25 and 100 AD, lists 64 places where gold and silver were buried or hidden.

The style of writing on the Copper Scroll is different to the others, and it has been theorised that the treasure listed was from a temple inventory hidden from Roman troops.

The scroll is on display at the Jordan Museum in Amman.

7. Gobekli Tepe, Turkey

Gobekli Tepe in Sanliurfa, Turkey, was built before the invention of the wheel and changed how anthropologists believed civilisation developed. EPA-EFE / Erdem Sahin

Gobekli Tepe is thought to have been built and occupied towards the end of the last Ice Age, between 9600 and 7000BC, during an era marked by the “beginnings of village life”.

The settlement, which pre-dates pottery and the invention of the wheel, has caused heated debate since it was discovered in 1963, sparking a re-evaluation about the evolution of civilisation, in particular concerning hunter-gatherers.

The planning and building of the site would have required organisation and resources that anthropologists believed were unknown in their societies.

The Neolithic archaeological site in the Anatolia Region is home to the world’s oldest known megaliths — huge stone pillars decorated with carvings of animals.

However, the lack of housing, cooking hearths and utensils at the site, point to evidence that it was not a settlement but perhaps a temple or place of worship.

8. Super-Henge, UK

Just more than three kilometres down the road from arguably the most famous henge in the world, Stonehenge, is another stone monument, built about 400 years after its neighbour.

Unearthed in 2015, Super-Henge is made up of a collection of stone monoliths found beneath the bank of a grass-covered, circular embankment called Durrington Walls.

Researchers believe the area, built about 4,600 years ago, was a settlement of up to 1,000 houses, home to about 4,000 people. Some have theorised it was where the people who built Stonehenge lived.

Archaeologists remain unsure about the purpose of the original 90 stones, although it may have made up part of a Neolithic monument. Neither do they know why the stones were later intentionally buried.

9. Thonis-Heracleion, Egypt

A 5.4-metre red granite statue from the fourth century BC, representing the god Hapy, is lifted from the seabed near Alexandria, excavated from the lost, sunken city of Thonis-Heracleion. Photo: Christoph Gerigk © Franck Goddio / Hilti Foundation

The Egyptian port city of Thonis-Heracleion served as the gateway to the Mediterranean, with origins dating to the 12th century BC.

Before the discovery of the ruins many archaeologists had thought Thonis and Heracleion were two separate cities on the Egyptian mainland, which had long been lost to the mists of time because it was barely mentioned in ancient texts.

In 1933, an RAF commander flying over Abu Qir Bay near Alexandria reported that he had seen ruins under the water from his bird’s eye view.

It wasn’t until 1999 that French underwater archaeologist Franck Goddio began a five-year excavation of the site, turning up coins, pottery and a statue of the queen Arsinoe II.

Later excavations found an ancient Nile river boat, temple, bridges, statues and sarcophagi.

It is thought that earthquakes, tsunamis, floods and soil liquefication caused the city to sink beneath the sea.

It is estimated that only 5 per cent of the city has been excavated so far.

10. Sacsayhuaman, Peru

As with Britain’s Stonehenge, Sacsayhuaman continues to present a headscratcher to archaeologists trying to figure out how the ancient civilisation moved and placed the 100-tonne stones at the site.

Although it was built in the 15th century, the site is thought to have been inhabited since 900 AD.

The stones used were cut and put together without mortar, resembling a jigsaw puzzle suggesting it was designed as it was being built.

The Incan stone structure in Cusco was initially thought to be a fortress or a place for ceremonies. But its true function remains unknown.