Around Carnac, in the Brittany region of France, stand more than 4,000 stones dating back 6,000 years. Some of them stand individually, some are aligned in rows, and some mark the sites of chambered graves beneath nearby mounds. Intricate burial chambers in Ireland, like many of the 12,000 ancient chambered burial sites beneath mounds in northern Europe, have arrangements of stone or markings that correspond with lunar and solar cycles. All of those ancient structures and arrangements of large stones are examples of a megalith (from the Greek "megas" meaning large, and "litho" meaning stone), a term used most specifically in reference to stone structures erected for ceremonial, astronomical, and religious purposes, and as monuments. Megalith building (placing large stones in a specific site) dates back to at least 5000 B.C.E. Many of the most famous megaliths were erected between then and 1500 B.C.E. The communities that erected them eventually faded into the recesses of history, but the megaliths they left behind continue to tantalize the imagination.
Adding to the mystery of these ancient structures is the supposition that they were erected by people not credited with possessing the knowledge and technology needed to move massive stones. Even if large labor forces were available, most megalithic structures demanded keen architectural and mathematical skills for planning and erection. Additionally, many ancient megaliths seem to have had sophisticated uses as solar and lunar calendars and as astronomical observatories. In fact, the discipline of archaeoastronomy (the study of astronomy among ancient societies) has become a burgeoning field of study during the past few decades, with ancient megaliths often serving as the focus of the discipline.
As ancient megaliths are studied, a greater appreciation for the skills and knowledge of prehistoric civilizations comes forth. Missing pieces of the puzzle of human development remain, however, fueling more speculation and theories. Perhaps survivors from vanished civilizations
Ancient megaliths are generally divided into five categories:
The greatest concentration of aligned megaliths is in the Carnac area of Brittany, France, where megaliths are aligned in rows in three different fields. Le Menec has two stone circles at either end of 12 rows of megaliths. The tallest stones stand 13 feet in height, and the stones dwindle in size moving from west to east, totaling 1,099 megaliths. Kermario has 10 rows and 1,029 megaliths. One tall menhir, in which five serpents are engraved, serves to signal a nearby tumulus, an earthen mound that covers a chambered grave. The third field, Kerlescan, has 13 rows of aligned megaliths that form the shape of a barrel.
The megaliths of Carnac first underwent radio-carbon dating techniques in 1959. At that time it was expected the results would show the megaliths were erected during the first or second century B.C.E., for it was generally believed that the megalith builders had come from the eastern Mediterranean region from Egypt, or Mycea (a civilization that preceded ancient Greece). The radiocarbon test, however, pushed the megalith builders back as far as 4650 B.C.E. All previous theories about the origins of the Brittany megaliths were undermined. The structures originated with pre-Roman and pre-Celtic civilizations, and they were older than similar structures in the eastern Mediterranean region from which the engineering expertise to erect the megaliths was previously believed to have originated.
The question of how the megaliths were positioned at sites where they stand is baffling. Modern-day tests conducted on moving the megaliths from quarries to nearby sites showed that it was possible for the primitive societies to move and erect the megaliths using rope or simply pushing the stones. Such effort, however, would have required coordinating the labor of hundreds of workers. One test during the 1970s showed that 200 people could move a 30-ton stone two to three miles in a few days by rolling the stone over logs.
Some monoliths (single blocks or large pieces of stone) are formed naturally and gain mythical importance based on their sublime appearance. In the Australian desert stands the world's largest monolith, Uluru (also called Ayers Rock), which reaches about a thousand feet high. Uluru is venerated by aborigines (native people of the area), who believe the ground beneath it is hollow and is a source of energy called Tjukurpa Dreamtime. According to their belief, all life as it is today is part of one vast unchanging network of relationships that can be traced to the spirit ancestors of the Dreamtime. The great spirits walked along the earth and literally sang material objects into existence.
The Uluru monolith extends downward more than three miles beneath the surface. Approximately 500 million years ago it was part of the ocean floor at the center of present-day Australia. Depending on the time of day and the atmospheric conditions, Uluru can dramatically change color, from a deep blue to glowing red. The area draws a variety of visitors, from those seeking to tap mystical energy, to tourists bussed in and out for a couple hours' worth of viewing time.
Among natural monoliths with mysterious qualities are "healing stones," usually a large stone with a hole through it. The Men-an-Tol in Cornwall, England, is one of several examples of a stone reputed to have healing properties. According to legend, people can be cured of back and leg pains by passing through the hole in the stone.