Clava Cairns Stone Circle South surrounds the southwest passage grave and forms part of the sophisticated astronomical alignment that makes this Bronze Age site one of Scotland's most significant prehistoric monuments. This stone circle, with its carefully graded standing stones, works in conjunction with the passage grave to frame the midwinter sunset on December 21st, creating a spectacular light show that demonstrates ancient Scottish understanding of celestial cycles. The circle represents the spiritual boundary around the sacred burial cairn, where Bronze Age communities gathered for solstice ceremonies and burial rites 4,000 years ago. While Diana Gabaldon used Clava Cairns as inspiration for Outlander's mystical Craigh na Dun, she had never visited when writing the first book, making the real site's spiritual power even more remarkable. The South Circle's connection to seasonal transitions and death-rebirth symbolism resonates powerfully with Outlander's themes of time travel and spiritual transformation across centuries.