The Sacred Centre

Both the Germanic and Celtic traditions have a concept of a sacred centre. One can see this in the sacred sites of Tara and Uisnech in Ireland and at Thingvellir in Iceland. The two Irish sites were described "like two kidneys in one animal" according to a Middle Irish source[Davidson, 1988].
It would be helpful to picture in your mind the sacred sunwheel or Eye of Woden when thinking about this concept.
The Eye of Woden is divided into 4 quarters just as Tara is symbolically the centre of Ireland around which the four kingdoms of Ulster, Connacht, Leinster and Munster are situated. Likewise the Icelandic Thingvellir is the symbolic centre of Iceland which in ancient times was divided into four quarters each having their own `Thing` or place of judgement. Thingvellir was the site of the Icelandic `Allthing`.
At such sites the Celts and Teutons at certain times of the year would recite the law, introduce new laws, try cases brought before the priests, chieftains or kings and inaugurate or proclaim new kings. These sites were symbolic of the centre of the cosmos and its very beginnings.
Hilda Ellis Davidson in her book, Myths and Symbols in Pagan Europe states "The pattern of four divisions round a central point is found in both Iceland and Ireland, and Mueller claims that this is a fundamental pattern in both Germanic and Celtic tradition."
This fourfold division reminds one of the fourfold division of the year and the four cardinal directions. Indeed one can see this same division in the Anglo-Saxon Futhorc with its 4 aetts of 32 Runes and its 33rd Rune Gar[the spear of Woden] placed at the centre of the 4 aetts when arranged in a circle. At the centre of both Tara and Uisnech sacred stones were erected: at Tara the Stone of Knowledge[Lia Fail] and at Uisnech the Stone of Division. An example of what these stones may have looked like is the Turoe Stone in County Galloway in Ireland. The stone is curiously dome shaped and its curious patterns are divided into four parts. The stone is said to resemble the Omphalos at Delphi, reckoned also by the ancient Greeks to be the centre of the world.
One of the principal sacred sites of the continental Germans was Eresburg, the location of the Irmunsul, a wooden column held sacred by the Saxons which corresponded with the mythical Scandinavian world tree Yggdrasil, the centre of the nine worlds of the Eddas. The Irmunsul was cut down by Charlemagne in 772. Irmin is considered to be an alternative name for the ancient Germanic sky deity Tiw. The Elder Germanic Rune stave Teiwaz is dedicated to this God and is shaped like a tree. Irmunsul like Yggdrasil supported the entire cosmos. In the Volsungasaga a tree is said to have supported the hall of Sigurd`s grandfather Volsung.
Significantly beneath Yggdrasil the Gods held assembly and so the link between a symbolically central site and divine communication and judgement is paralleled.