The Dinnseanchus, a topographical work, compiled in the twelfth century from ancient MSS., is the principal source of information on this subject.  Dr. Petrie, in his famous Essay, has given both the original and translation of this tract, and of other documents on the same subject; and he remarks how exactly the accounts given by the poet historians coincide with the remains which even now exist.  In fact, each site has been ascertained with precise accuracy—­an accuracy which should very much enhance our appreciation of the value of our ancient histories.

The well Neamhnach was first identified.  Tradition asserts that the first mill[174] erected in Ireland was turned by the stream which flowed from it, and even at the present day a mill is still worked there.  The situation of the Rath-na-Riogh was then easily ascertained.  This is the most important of these ancient sites, but it is now, unfortunately, nearly levelled to the ground.  This rath is oval and measures about 853 feet from north to south; it contains the ruins of the Forradh and of Teach Cormac (the House of Cormac).  A pillar-stone was removed in 1798 to the centre of the mound of the Forradh.  It formerly stood by the side of a small mound lying within the enclosure of Rath-Riogh.  This stone Dr. Petrie considers identical[175] with the famous Lia Fail, or Stone of Destiny, which other authorities suppose to have been removed to Scotland, and subsequently to Westminster.  The Rath-na-Riogh is identical with Teamur, and is, in fact, the ancient Tara, or royal residence, around which other scarcely less important buildings were gradually erected.  It was also called Cathair Crofinn.  The name of Cathair was exclusively applied to circular stone fortifications built without cement; and stones still remain which probably formed a portion of the original building.  In ancient Irish poems this fortification is sometimes called the Strong Tower of Teamur, an appellation never applied to a rath, but constantly to a Cathair, or circular stone fort.

The Rath of the Synods obtained its name at a comparatively recent period.  The situation is distinctly pointed out both in the prose and verse accounts.  Here was held the Synod of Patrick, the Synod of Ruadhan and Brendan, and lastly, the Synod of Adamnan.  The next existing monument which has been identified with certainty, is the Teach-Miodhchuarta, or Banqueting Hall, so famous in Irish history and bardic tradition.  This was also the great house of the thousand soldiers, and the place where the Fes or triennial assemblies were held.  It had fourteen doors—­seven to the east and seven to the west.  Its length, taken from the road, is 759 feet, and its breadth was probably about 90 feet.  Kenneth O’Hartigan is the great, and indeed almost the only authority for the magnificence and state with which the royal banquets were held herein.  As his descriptions are written