Bocan Stone Circle 4 -5000 BC It is thought that the Bocan Stone Circle was probably built as a sun temple some 4000 – 5000 years ago. It has a diameter of approximately 20 metres and seems to form two arcs, with seven of the stones still standing out of the original 30 or so, some of which would have been up to 2 metres tall. The stone circle may be aligned on an east-west axis between Slieve Snaght, the highest mountain in Inishowen and Jura an Island in Scotland.