The hill of Sheemor is a limestone hum, an extra hard chunk of rock that was too tough for the glaciers, close to Leitrim Village in the middle of County Leitrim.
Though it looks like a small hill, the summit of Sheemor rears up above the surrounding plain to a height of 178 meters above sea level. From a distance the hill looks strangely like a large altar, especially since the central and largest of the three neolithic cairns on the flat top, now supports a large modern Christian cross at the highest point. As if that wasn't strange enough, the cross is illuminated at night, and seems to float in the sky over the surrounding countryside.
The large central cairn is about 22 meters in diameter and 5 - 6 meters high, and as far
as we know, has never been opened. The cairn is built with chunks of limestone quarried from the edges of the hill close by. The cross was erected in 1950 to mark the Catholic
definition of the dogma of the assumption. Though a visitor might think it out of place in this modern liberal age, the cross on Sheemor is a popular local landmark, which is visible from many miles around.
Sidhe Beg and Sidhe Mor by OPW guides Pádraig and Martin at Carrowmore.
The two smaller cairns on the left and right are quite disturbed, and chamber
or passage-slabs can be seen amid the stones, and the sites obviously
date from the Neolithic, over 5,000 years ago. The large cairn, though
much disturbed by the cross, remains unopened. This site lies between Carrowkeel and Loughcrew,
Music and folklore
The name Sheemor means Great Fairy Hill, and there is another complimentary site called Sheebeg a few miles away, also with a large neolithic cairn on the much lower summit. According to local traditions two local fairy tribes went to war with each other, the event being remembered for the enormous noises when the two armies met between the sidhes. The Battle of the Fairy Mounds was made famous by a tune allegedly composed by the blind traveling harper Turlough Carolan.
International Dance Day - Sean Nós ar an tSionann dancers on Sheemor.
According to tradition, Carolan fell asleep at Sheebeg and heard the music of the fairies through the mound, and when he awoke he composed the famous melody. Alas, it has been discovered that the tune predates Turlugh Carolan ( 1670 - 1738 ), and originates in Scotland. Whatever the truth it is a good story and is still a popular traditional tunes in Irish music sessions.
From an archaeo-astronomical perspective, Sheemor has a fascinating connection with Knocknarea some 40 kilometers to the north-west. Knocknarea is visible on the horizon from Sheemor and marks the position of sunset at midsummer, and the same event can be witnessed from Shee Lugh, the cairn on Moytura . Conversely, Sheemor is visible, given the right conditions, from the summit of Knocknarea. It is highly unlikely that this astronomical connection is accidental or was unobserved in neolithic times; on the winter solstice the sunrise, viewed from the platform summit of Queen Maeve's Cairn, will rise over the distant marker of Sheemor.