Callanish Standing Stones

I'm finally home and catching up with the blip entries from my motorhome holiday in the Outer Hebrides. We visited the Callanish Standing Stones on the Isle of Lewis. They are very atmospheric, particularly the secondary circles, Callanish 2 and 3, where there are less visitors and more sense of space and remoteness. This is Callanish 3. Wikipedia tells me construction of the site took place between 2900 and 2600 BC. Quite astonishing.