Stonehenge's Scottish connection.

Stonehenge's altar stone, weighing 6 tonnes, has been identified as coming from north-east Scotland, making it the stone that was transported the furthest in the megalithic structure. The stone is believed to have been brought to Stonehenge by sea, as evidence suggests that people were making sea journeys during that time. Stonehenge is unique in the distance that its stones were transported, with most stone circles being made from rocks found within a kilometer of the site. The altar stone is made of Old Red Sandstone from the Orcadian basin in north-east Scotland, with the nearest matching source rocks being 750 kilometers away. The reason for bringing the altar stone such a long distance remains unknown, but it provides insight into the Neolithic society and its connectivity. [Extracted from the article]