Stone circles number 1, 000 across the country, while there are around 120 henges known.

BBC: Discovering Britain��s prehistoric stone circles

Then there's a very last phase of use at stone circles which is perhaps more northern than southern.

BBC: Discovering Britain��s prehistoric stone circles

You've got plenty of stone circles that don't have henges, and plenty of henges that don't have stone circles.

BBC: Discovering Britain��s prehistoric stone circles

The group of Neolithic monuments on Orkney include a large chambered tomb and two ceremonial stone circles together with a number of unexcavated burial, ceremonial and settlement sites.

UNESCO: World Heritage

One face of the hill had been almost completely excavated, exposing four stone circles, each made up of a dozen or so pillars with two larger pillars in the middle.

NEWYORKER: The Sanctuary

Nevertheless, stone circles and henges do appear to be connected parts of a tradition that developed in Britain from around 3000 to 2000 BC - in other words, during the later Neolithic period (when agriculture began here) and moving into the earlier Bronze Age (when we see the first use of metals, from about 2400 BC).

BBC: Discovering Britain��s prehistoric stone circles

The canals that ring the city in tight concentric circles are lined with 3, 000 of them, moored to centuries-old stone quays.

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