In the ordinary course of development certain nuclei for everyday shopping, with possibly a post office, bank, etc., tend to form themselves not always in the most suitable places. They usually occupy the sites of former villages, or are situated at newly developed cross roads. Modern planning includes among its aims guidance as to the situation of such centres. In dealing with the area falling between the built-up city and the green belt, it is proposed that these neighbourhood centres should be so placed that no house shall be more than half-a-mile from a centre. Where an area is at present undeveloped, it is impossible to define the exact situation of such a future centre, but its approximate situation is shown as a diamond on the map. Existing centres working into the pattern are shown to their existing shapes, allowing for increased size. It can be seen, therefore, that the structure of the Dublin plan is not only that formed by the street pattern, but by a series of circles-the city within the circular roads being the larger central nucleus, with the half mile circles surrounding it, each having its focal centre.

It is only by means of a theoretic basis of this sort that a topographically satisfactory social structure can be built up. Dublin, being an ancient city, with not only a well marked historic centre but also, especially on the South, a markedly developed suburban growth, it is clearly impossible to realise an ideal theoretic diagram; but the principle of a city built up out of units of neighbourhood life culminating in the civic centre should be adopted.

The open strips described under "Parkways" in Section 6, have been planned as much for the purpose of breaking up the monotonous continuity of suburban spread and creating neighbourhood units as for the provision of space dedicated to recreation. It will be seen, on the 8-inch map (No.2), that this new form of fringe growth produces a pattern different from that found in the older suburbs.