It is 1971 and the August heat beats down on the Wiltshire countryside in southern England.

Five free-spirited teens who've spent their summer traveling the country in a campervan

popping from one festival to another are on their way to their final destination, an unofficial

campsite on Salisbury Plain. As their van crests a hill, it comes into view, Stonehenge.

The behemoth stands tall and inscrutable against the rolling green hills. The ancient ruins

are comprised of a partial outer ring of vertical sars and stones that stand about 13 feet

tall and 7 feet wide, some still possessing their stone lintels.

And in the centre of it all, stands what's left of a series of trilathons, huge, stand

alone in shaped structures which together once stood in the shape of a horseshoe, three

still stand complete, each around 20 feet high. They look like giant portals to some other place.

Another vast stone of the inner sanctum lies flat on the ground, leading some to belief it may

have been some kind of altar. The five teenagers are mesmerised as they draw ever closer,

even at a distance, the vastness of the stones and their weighty presence is palpable.

Just beyond it lies what's known as a heelstone, a single outlying standing stone to the northeast.

The kids in the van think back to the summer solstice two months before, when they,

along with many of their friends, gathered there to watch the sun rise,

it crested the horizon just to the left of the heelstone. Many years before,

a second stone had stood there too, the pair of them perfectly framing the rising solstice sun.

As the five friends continue on their way, they talk about how it all might have once looked,

the perfect, completed circle of the outer ring, the giant,

trilathon stones inside, the tallest of which would have towered over the others at 24 feet high.

Debate surrounding what's left of the stones that litter the inner circle continues to

...