Ballyvennaght : Portal Tomb

Two stones place either side of a gallery, opposite each other, but not touching so as to leave a gap, that are used to segment it into smaller chambers.

Standing stones, also called menhirs or monoliths, are the most simple of megalithic monuments. They are exactly what they say, a stone that stands with one end set into the ground. Being simple in form does not make them simple to understand, for they have served several purposes over time. Some were placed to mark burials, others were probably erected to mark boundaries or travel routes, the purpose of others is uncertain, but it may well have been ritual.

Standing stones can vary enormously in size from a under 1m tall to over 4m. Some have been purposely shaped (see Stone Of Destiny (County Meath)) and some must have been chosen purely for their shape (see Ballyvatheen (County Kilkenny)). Most standing stones are dated to be from the Bronze Age, but some are clearly older, especially those associated with passage tombs such as at Knowth (County Meath) and Loughcrew - Corstown (County Meath).

Others have been re-used in later times (see Kilnasaggart (County Armagh) and Breastagh (County Mayo)), perhaps to try and capture some of the powers of the old gods or to legitamise a claim to land.

Wedge tombs are most easily catagorised by their main characteristic - they are taller and wider at the entrance than they are at the rear. Like court tombs they have a gallery which is split either by septal slabs or sill stones into smaller chambers. Galleries can be anything up to 8m in length.

The side walls are, uniquely, made of two rows of stones (three in some cases), which is refered to as double or triple walling. This double walling is perhaps the best feature to identify a wedge tomb by.

The roofs are constructed by laying large blocks or slabs across the gallery, resting on the tops of the walls.

They are often quite small, an amazing exception being Labbacallee (County Cork), one of the largest in Ireland. It is very rare to find a wedge tomb with its roof still in situ, although, occasionally, one or two of the roof slabs are present (see Proleek (County Louth)).

In some examples the roof would have extended beyond the front closing slab forming a portico at the front, which in a few specimens was split by a vertical stone place centrally in the entrance.

Like court tombs, portal tombs and passage tombs they were covered by a cairn, which, at many sites, it is still often possible to determine. A few, such as Burren SW (County Cavan), still retain a large proportion of the cairn.

The large rock used to form the roof of a portal tomb or kist.