"All the above questions lead inexorably to the Why? questions, although these are perhaps the first that come into most people’s minds. Why were these monuments built – why here, why then, why at all? What was their purpose? ... It can be tempting to propose grand schemes of interpretation, as if we have some special access into past world-views, but speculations, lacking a solid and testable evidential base, should not take the place of reasoned interpretation. That is not to say that that speculation has no value, since informed curiosity can suggest avenues for fruitful research, but answers need evidence, and it is through carefully considered research that such evidence is most effectively sought."