For centuries they were the subject of intrigue and speculation, but the true nature of the Dilmun Burial Mounds, discovered in Bahrain, has been known for barely 60 years. Thousands of the mounds on 21 archaeological sites exist on the island nation, but it was an expedition lead by an oilman-turned-archaeologist and former Second World War resistance fighter, that unearthed the connection with Dilmun – a lost empire many believed existed only in myth. Geoffrey Bibby studied as an archaeologist at the University of Cambridge in the UK but, after serving as an intelligence officer in the war and at one point fighting alongside the Danish resistance, he could not find work when the conflict ended. He went on to take a job with the Iraq Petroleum Company – which would become British Petroleum and then BP – and, in 1947, moved to Bahrain. There he had his first encounter with the country's ancient and unexplained mounds, or tells, a word derived from the Arabic tal, for a small mound or hill. A series of fortunate events would bring him back six years later. When back in Britain, Bibby married a Danish woman, Vibeke Tscherning, who was a friend of Peter Glob, a noted Danish archaeologist with an interest in the Middle East. In conversations with Bibby, Glob learnt of the Bahrain sites with growing interest. With the support of the Ruler, King Salman bin Hamad Al Khalifa, and his generous offer of £3,000 (worth about £85,000, or $116,785 today) the two men arrived in Bahrain in 1953 to begin excavations. Previous archaeological digs had taken place first in 1906 and then on a larger scale in 1920, but found little more than stone chambers inside the mounds, along with a few bones and some broken pottery. The conclusion was that Bahrain was uninhabited at the time, serving only as a giant cemetery for the tribes of mainland Arabia. Another theory was that the chambers had been built by the Phoenicians of the Eastern Mediterranean, while some local Arabs claimed they were the graves of Portuguese colonial invaders, who built a massive fort in the 16th century over one of the largest mounds. All were wrong. As Bibby and Glob would begin to reveal over the next two decades, Bahrain was the heart of an ancient maritime empire, whose name had vanished until the first translations of 4,000-year-old Sumerian clay tablets in the 1850s. Dilmun, according to the cuneiform poetry scripts “is pure”. <em>In Dilmun no cry the raven utters</em> <em>Nor does the bird of ill-omen foretell calamity</em> <em>The lion kills not, nor does the ravening wolf snatch away the defenceless lamb.</em> <em>Unknown is the wild dog who tears the kid</em> <em>The dove does not conceal its head</em> <em>The maiden walks here in innocence</em> <em>No lustrations need to be poured</em> <em>The sombre death priest walks not here</em> <em>By Dilmun's walls he has no cause for lamentations.</em> This paradise on Earth was sometimes compared with the biblical Garden of Eden. It is described in the <em>Epic of Gilgamesh</em>, an account of a mythical hero believed to have been written 4,000 years ago, and which survives on a series of 12 clay tablets from the seventh century BCE discovered in modern-day Iraq. Part of the poem tells how Gilgamesh travels to a sacred island to obtain the secret of eternal life from Ziusudra, whose own life was spared when humanity was wiped out by a great flood sent by Enki, the Sumerian god of water and creation. Despite these, and several other references, there was no reason to believe Dilmun actually existed, let alone that it was present-day Bahrain. Glob and Bibby’s discoveries told a different story of a lost civilisation. Two of the most spectacular finds were the Barbar Temple, with a sacred well dedicated to Enki, and a palace underneath the Portuguese fort, Qalat Al Bahrain, along with seals and weights, which confirmed trading links from Ur, in southern Iraq and the civilisations of the Indus Valley, now north-west India and eastern Pakistan. This places Bahrain, as Dilmun, as the centre of this vast Bronze Age trading empire. Copper was a major source of income, imported from Oman and refined along the Gulf, including the Abu Dhabi islands of Dalma and Sas Al Nakhl, both identified as part of the Umm Al Nar Bronze Age culture, and with possible connections to another lost civilisation, Makan. Other evidence strengthens the theory that Bahrain was Dilmun – both the mythical and real versions. The god Enki is lord of freshwater, while life on the island has long been sustained by its underground springs, some of which bubble from the sea with such force they can be collected, untainted by salt, by dipping a bucket. Then there is the flower of the sea, which Gilgamesh seeks for its ability to give him immortality. The hero retrieves it by diving with stones attached to his feet. Here are clear parallels with pearling, practised by Bahrainis from even before the age of Dilmun. This is also listed by Unesco on its world heritage list, along with a third entry, the tell at Qalat Al Bahrain, which includes the Portuguese fort and the harbour from which the traders of Dilmun set sail. Gilgamesh also tells that the flower of the sea – or pearl – was stolen by a snake, which achieved immortality by shedding its skin. The Danish archaeologists discovered evidence of a snake cult, with several graves containing clay pots with a snake skeleton curled inside. The long-dead serpents did not, of course, confer any protection to the human occupants of these graves but their discovery, and the connection that can be made with Bahrain and Dilmun, lost and then found, can perhaps now be seen as a kind of immortality. It is nearly two years since Unesco, the United Nations science and cultural organisation, awarded World Heritage Status to Bahrain’s Dilmun Burial Mounds. After 4,000 years, what was once one of the world’s greatest mysteries had finally been officially recognised.