The Ardmore Gallen Stone stands in a field near the village of Muff in Co. Donegal. More than 10,000 standing stones have been recorded in Ireland which was used for marking tribal boundaries, ritual locations, or for possibly marking a burial chamber. They are difficult to date as some were erected as late as the 18th century as scratching posts for cattle but this one probably dates from c.500-1500 BC. Many are plain and undecorated but this stone has numerous cup-marks (small depressions) and swirling patterns carved into it which can be dated to the Bronze Age. It stands over six feet tall and is nearly three feet wide so it is not just an ordinary old stone made to stand up in a field. There are hundreds of theories that suggest different meanings for these carvings but the latest leading theories suggest they must be some sort of early recording system for the seasons or for star constellations.