There is uncertainty about the usage of these ancient runes. They remain quite a mystery to date and I am sure you are familiar with that. No one has been able to figure out their purpose to the dot. The most famous theory is that it was built as an astronomical observatory and others state that it had some religious purpose. But too bad, I guess we will never know. Nevertheless, the construction began around 3000BC. How do you think it was constructed? Do you have any idea what it was used for?