One of the most intriguing mysteries regarding Stonehenge is how the massive stone arrived from such a long distance away. A typical saddens tone weighs 25 tonnes, whereas bluestones are approximately 2 and 5 tonnes. There are several ideas as to how these stones came to Stonehenge, including the theory that glaciers transported the bluestones across. The most plausible idea is that they were hauled over land by humans utilizing a network of canals.