This is one of those "I suck as a celtophile" moments. I've never been to Emain Macha - one of two central locations in the Tain bo Cualnge cycle, the home of Cuchulain (oh yeah and Conchobar mac Nessa himself).. I. Suck. But I am well aware of how much I need to go at some point.
Annals of Ulster Annála Uladh TCD 16th century. Vellum This manuscript contains Irish annals for the years 431-1504 AD. Its principal scribe Ruaidhrí Ó Luinín was a member of a hereditary learned family, historians to the Maguires of Fermanagh. The Annals of Ulster were compiled on Lough Erne, Co Fermanagh under the direction of Cathal Óg mac Maghnusa, archdeacon of Clogher.
Lóegaire mac Néill - Lóegaire (floruit fifth century) (died c. 462), also Lóeguire, is said to have been a son of Niall of the Nine Hostages. The Irish annals and king lists include him as a King of Tara or High King of Ireland. He appears as an adversary of Saint Patrick in several hagiographies. His dealings with the saint were believed to account for his descendants' lack of importance in later times.
Glendalough, County Wicklow, Ireland. This area, whose name means valley of two lakes, is home to one of the oldest monasteries in Ireland, as well as two beautiful lakes and a few other sites of historical interest (most of which are connected with the monastery). It is a great place to go see if you're in Dublin as it is quite close by.
Must See: Dublin. Best explored on board of one of the numerous bus tours or on foot, Dublin is relatively small. It is however rich in history as well as full of sights and museums. Dublin can keep the tourist busy for a whole week! Avoid the city center on Saturdays when half the population of Ireland seems to go shopping here!
and this is the other half of the "I am a bad celtophile" admission - I have also not been to Cruachan/Rathcrogan - the seat of Ailill and Medb in Connacht. The other central locale in the Tain bo Cualnge.