Ballynoe Stone Circle is a prehistoric monument located in County Down, Northern Ireland. It consists of a circular arrangement of large standing stones, with a central stone known as the altar stone. The site is believed to date back to the Bronze Age, around 2000 BC, and is thought to have been used for ceremonial purposes. The stone circle is approximately 30 meters in diameter and features 24 stones, some of which are over 2 meters tall. It is part of a larger complex of ancient sites in the area, highlighting the rich archaeological heritage of Ireland. Visitors can explore the site and appreciate its historical significance.