Loughcrew Cairns form the largest complex of Passage Graves in Ireland. The Cairns are megalithic structures containing symbolic engravings. Like other passage graves in Ireland, they have clear astrological alignments. There is evidence of many uses during the millenia, but it is generally agreed that they were originally built about 4000/5000 bc as burial chambers. They were excavated by amateurs at the beginning of the twentieth century, when many of the artifacts were removed. A blessing in disguise, perhaps, as recent archaeological scholars have concentrated on despoiling less explored sites, leaving Loughcrew relatively undeveloped and unknown; the best kept secret in archaeological Ireland.
In a landscape of inspiring beauty and intriguing history, Loughcrew is rich in historical and archaeological, religious and natural interest. One of ancient Ireland's major roads passes through Loughcrew, crossing the great Road of the Chariots nearby. The lakes abound with cranógs, and the drumlins are topped with innumerable motte and bailey forts. The remarkable Loughcrew Gardens, partly dating from the seventeenth century, and the Family Church of St Oliver Plunkett are nearby.