the homes of ancestral gods. He believes the mound was made as a platform on which druids would perform ceremonies and on which kings would be crowned, while drawing power and authority from the gods and ancestors. It is possible that each part of the monument represents something. The stones inside the wooden structure may represent souls in the house of the dead, or the souls of fallen warriors in their equivalent of Valhalla. Another theory is that the monument symbolizes a union of the three main classes of society: druids (the wooden frame), warriors (the stones) and farmers (the soil). The central pillar could also represent the world pillar or world tree linking the sky, the earth and the underworld. The radial pattern of the stone cairn may represent the sun wheel, a symbol associated with Celtic sun or sky deities. Dr Lynn writes: "It seems reasonable to suggest that, in the beginning of the first century BC, Navan was an otherworld place, the home of the gods and goddesses. It was a Celtic tribe's sanctuary, its capitol, its sacred symbol of sovereignty and cohesion". A recent study used remote sensing (including lidar, photogrammatry, and magnetic gradiometry) to map the site, and found evidence of Iron Age and medieval buildings underground, which co-author Patrick Gleeson says suggests that Navan Fort was "an incredibly important religious center and a place of paramount sacral and cultural authority in later prehistory". In Irish mythology In the Ulster Cycle of Irish mythology, Emain Macha is the royal capital of the Ulaidh, the people who gave their name to the province of Ulster. It is the residence of Conchobar mac Nessa, king of Ulster. He is said to have had a warrior training school at Emain. Conchobar's great hall at Emain was called by medieval writers in Chraebruad (the red-branched or red-poled edifice), and his royal warriors are named the Red Branch Knights in English translations. Emain Macha is said to have been named after Macha, who is believed to have been a sovereignty goddess of the Ulaidh. One tale says that Macha, queen of the Ulaidh, forced her enemy's sons to dig the great bank-and-ditch after marking it out with her neck-brooch (eomuin), hence the name. In another tale, Macha is the fairy wife of Crunnchu. Despite promising not to speak of her, Crunnchu boasts that his wife can outrun the king's horses.