Stonehenge is a megalithic structure located on Salisbury plain in England. Probably, it is the world's most famous megalithic monument of this kind. Similar structures, representing some vertical oblong stones (menhirs), arranged in a circle or spiral, can be found throughout Europe, the Caucasus and other parts of the world. In the UK and Ireland these cromlechs are not uncommon. And quite plausible theory that in Britain these cromlechs were a single system.

Stonehenge is surrounded by a moat and rampart pad with a diameter of about one hundred feet away. In the center is the Altar stone – a massive monolith of Sandstone. It is surrounded by five pairs of stones with lintels on top (the trilithon) installed in the shape of a horseshoe and is open to the North-East. At the base of the horseshoe is the highest rocks, to the ends of the horseshoe, their height is reduced. Horseshoe surrounded by a ring of so-called blue stones. They are bluish on the chip and turn blue if they are wet. Further Sarsenova the trilithons form a ring with a diameter of 33 metres. A total of 30 stones, the arc of the 13 stones preserved along with the upper rocks. They were established on the principle of "groove and tongue". These stones are surrounded by two concentric rows of 30 holes (so-called Y and Z holes). Closer to the ramparts and the moat is a circle of 56 pits known as Aubrey holes" - the surname of the researcher who found them. To the South is the small entrance, and is considered the core of the North-Eastern entrance, which opens onto the alley bounded by parallel ditches and banks leading to the river Avon. The alley is called the "Heel stone".

Consensus about the Dating of Stonehenge does not exist, however, many scientists tend to believe that the first phase of construction - the moat and ramparts should be attributed to ~ 3000 BC, although the earliest traces of human activity at this site date back to 8000 BC 2600 BC set blue stones. It is noteworthy that the Deposit of this stone recently opened in 1923. This district Presley in South-West Wales, 200 miles from Stonehenge. Perhaps from the same place and brought the Altar stone. As they were transported a separate mystery for archaeologists and historians that list a variety of technologies: and wooden rollers, and skids, and the method of "walking stones", and transporting units across water. In the next 200 years were installed Sarsenova trilithon, expanded northeast entrance and paved walkway.

The purpose of Stonehenge remains a mystery. Put forward a variety of versions, the most common one is that it is a sanctuary and place of burial. Also plausible hypothesis that Stonehenge was used as an Observatory – he quite accurately oriented to the sun and the moon in several areas that can't be a coincidence. Along with these there are and the most fantastic versions: for example, that Stonehenge is a landing pad for alien spaceships, or that these are the ruins of a nuclear power plant of the Atlantean civilization.