The smaller bluestones used in the center ring weigh 4 tons each, and had to be brought 240 miles from Wales. The larger outer ring stones are 50 tons each, and came from 20 miles away. The tallest stone is 30 feet high - with 8 feet of that being underground.
The stones are mentioned by Geoffrey of Monmouth in a 12th century work, where he claims that Merlin brought the stones in by magic and that Arthur was buried beneath them. Over the years, many theories about their construction have been offered, with many claiming that the druids were responsible for them. However, with the date of creation now set 2000 years BC, most believe that the indigenous people of England, who were just forming communities at this point, built the stone circle to help track time and important events.
The principle axis of Stonehenge is oriented to line up with the sunrise of Summer Solstice, in mid-June. The sunrise comes up visible in one of the arches, right above the �heel stone�.
There are also �Aubrey holes�, named after John Aubrey, who discovered them. By putting markers in these holes, you can track the position of the moon and sun - and even determine when there will be eclipses.
Stonehenge is now managed by English Heritage.
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