Last year, General Lefroy excavated a tumulus at Greenmount, Castle Bellingham, about five miles north of Calliagh Birra's so-called house.[263] In it he found a chamber, 21 feet long by about 4 feet wide and 5 feet high, enclosed by two parallel walls built of small stones, and closed at each end by similar masonry. The roof was formed of slabs in two rows, the lower projecting as brackets and the upper stretching across beyond the walls on each side. In plan, therefore, it was identical with the Birra's house, though longer and larger. But, from the mode in which it was constructed, it was evidently more modern,--the most modern, in fact, of all the chambered sepulchral tumuli yet discovered in Ireland. [Illustration: 81. Plan and Section of Chamber in Greenmount Tumulus. From a drawing by General Lefroy.] Nothing was found in the chamber: it had been rifled before, but by whom and at what period there was nothing to show. At 9 or 10 feet below the summit, but still 6 or 7 feet above the floor of the chamber, a bronze monument was found with a Runic inscription on it, which, with the assistance of the Danish antiquaries, the General decides to belong to the ninth century (852?). The one question is, is it coeval with the building of the tomb or its destruction? The name Domnal, or Domhnall, being Irish, and the position in which it was found seem to prove that it belongs to the period of the raising of the mound, not to that of its being rifled; and if so, this grave approaches the age to which Maeshowe in the Orkneys may belong. The circumstance, however, which interests us most at present is the similarity of the Greenmount Chamber to the Lady Birra's tomb. Being locally so close to one another, and so like in plan, they cannot be very distant in date, though the more southern is, from its megalithic character, undoubtedly the more ancient of the two. If we allow two or three centuries it is a long stretch, though even that takes us far away from any connexion with the monuments at Lough Crew, and barely allows of it following very close on those at Brugh na Boinne. The similarity of this tomb with those at Glen Columbkille has already been pointed out, and no doubt others exist in Ireland, and will be brought to light as soon as attention is directed to the subject. But meanwhile they seem, so far as we can at present judge, to make up an extensive group of pagan or semi-pagan monuments, extending from the time of St. Patrick to that of St. Columba, and, as such, are among the latest, and certainly among the most interesting, monuments of the class in Ireland. [Illustration: 82. Dolmen of the Four Maols, Ballina.]