Hello. I was hoping to have a professional's opinion on the theory that there was a city somewhere in Ireland during ancient times. This theory is based on the writings of Ptolemy. In his writings and on a map he referred to a location known as Eblana. He stated that this was a "polis" or "civitas," both of which would have a rigid definition as a nucleated, well organized settlement. While Ptolemy refers to this there is no evidence of any settlements at the time larger than a village. Should this theory be further explored or is it too far fetched?
So, as someone who's period of study is the later Irish Iron Age and as somebody who has done commercial archaeological fieldwork in North county Dublin and in Meath, which is where Eblana is roughly supposed to be located, it would be my opinion that the existence of a hitherto totally unknown, large, complex, urban (for a given definition of Urban) Iron Age site is highly unlikely.
The first reason for this is modern; the area of Ireland we're talking about has been inhabited continuously for a long time and is some of the better farmland in the country. That means deep ploughing, and, in recent years, road construction, housing development, and industrial development. None of this has uncovered any Iron Age sites that could be reasonably described as being similar to a Greek polis. All the sites I have excavated on in advance of development have been ploughed to some extent, very often disturbing archaeological layers. I find it difficult to believe a site of the kind you're talking about could have existed without it having been discovered before now.
Secondly, the Irish Iron Age is defined, as you say, by small settlements. The population of the island appears to have dropped significantly around the end of the Bronze Age and slowly recovers over the course of the Iron Age.
To make some general remarks and maybe keep discussion going. Why do we (we being previous scholars) think that "polis" and "civitas", when applied to people and places far to the edges of the Greek and Roman world, must mean the exact same thing as they do in the centre of those worlds? Could the person who wrote down the label have been trying to make sense of a concept that his audience (or he himself) would not have understood? Could he have misunderstood his source? Could he have been massaging the truth for the purposes of making a political point?