Proleek Dolmen - 3000BC, Portal tombs have two tall stones at the front (portal stones) and a smaller stone at the back supporting a large capstone. A portal tomb resembles a giant’s table and is sometimes called a ‘dolmen’, which comes from the Breton word tolmen meaning ‘stone table’. Proleek Portal Tomb is about 3m high and has a huge capstone weighing approximately 35 tons, Co. Louth, Ireland