Lunar standstill

At a major lunar standstill, which takes place every 18.6 years, the range of the declination of the Moon reaches a maximum. As a result, at high latitudes, the Moon's greatest altitude (at culmination, when it crosses the meridian) changes in just two weeks from high in the sky to low over the horizon. This time appears to have had special significance for the Bronze Age societies who built the megalithic monuments in Britain and Ireland, and it also has significance for some neo-pagan religions. Evidence also exists that alignments to the moonrise or moonset on the days of lunar standstills can be found in ancient sites of other ancient cultures, such as at Chimney Rock in Colorado and Hopewell Sites in Ohio.