Stonehenge in South England.

Interpretations break up at the stillnes of the stones since thousands of years.
One assumes four building periods between about 3100 BC and 1500 BC.

The sarsen blocks, with a weight of up to 50 tons, were brought from Marlborough
Downs 30 kilometers away. With wood and soil ramps on rolls, and on ice in winter,
the monoliths were brought in place and piled up.

A considerable achievement for the stone age people, who didn't have anything
important to do than to build a huge stone calendar, and thereafter recongize when it is summer and winter?