The Táin: Queen Medb's Raid on Cooley

The raid starts with a quarrel in bed at Cruachan, Medb's royal seat. She and Ailill have all their goods brought out and counted, and the only difference is Ailill's bull Finnbennach, the Whitehorned, who had been born in Medb's herd but refused to belong to a woman. When the owner of the Brown Bull of Cooley breaks his promise to lend it, Medb gathers an army. Rathcroghan, near Tulsk, is identified with Cruachan: some 240 ancient sites over six square kilometres, including Oweynagat, a cave long called a gateway to the Otherworld.

Visitor guidance: Start at the Cruachan Aí visitor centre in Tulsk, which explains the monuments scattered across the surrounding fields.

The host crosses the Shannon near Athlone and marches through Meath while Ulster lies helpless under the curse of Macha, from the beginning of November until February. Cú Chulainn, guarding the border alone, kills the invaders by the hundred until Medb agrees to send him one champion at a time. Meanwhile her men scour the hills of Cúailnge, and she carries off the Brown Bull. The Cooley peninsula, between Dundalk Bay and Carlingford Lough, is ringed by the Cooley Mountains, made of 60-million-year-old volcanic rock.

Location precision: The bull's hiding place is not identified; the pin marks the Cooley peninsula.

Visitor guidance: The medieval village of Carlingford is the base for walks in the Cooley Mountains.

Medb's last hope is Ferdiad, Cú Chulainn's foster-brother and best friend, whom she wins over with her daughter Finnabair's hand and the threat of being mocked as a coward. Cú Chulainn begs him not to fight. For days the two meet at the ford, fight from dawn to dusk and at night send each other food and healing herbs, until Cú Chulainn kills Ferdiad with his terrible spear, the Gáe Bolga, and weeps over him. Ardee takes its name from the fight: Áth Fhirdia, "Ferdia's Ford" on the River Dee.

Location precision: Ardee's name preserves the tradition; the ford itself is legendary.

Visitor guidance: A bronze statue of Cú Chulainn carrying the dead Ferdiad stands on Bridge Street, beside the river; Ferdiad's grave is said to be on the south bank.

With Cú Chulainn wounded, Medb's army plunders Ulster up to the walls of Emain Macha, King Conchobar's capital, until the Ulstermen finally wake from their curse. The curse itself began here: the goddess Macha, forced by the king to race his horses while heavily pregnant, gave birth at the finish and cursed the men of Ulster to suffer a woman's labour pains in their hour of need. Emain Macha is Navan Fort near Armagh. Inside its ring, a huge timber building, its central oak post felled in 95 BC, was filled with stones, burnt and buried under the mound.

Visitor guidance: The Navan Centre beside the fort tells the stories of the Ulster Cycle; the mound is a short walk across the fields.

The Ulstermen win the final battle and Medb retreats, but she has the Brown Bull. At Cruachan he meets the Whitehorned, and they fight all night across Ireland. The Brown wins, and carries his rival's body home, dropping pieces as he goes. At the Shannon, says Dunn's text, he "left behind the loin of the Whitehorned", hence Athlone, "Loinford"; the liver gave Trim its name. Back in Cooley his heart bursts. The real Athlone means "Luan's ford", but the storytellers' version is better.

Location precision: A legendary place-name story; the pin marks Athlone Castle at the Shannon crossing.

Visitor guidance: Athlone Castle, by the bridge over the Shannon, houses a visitor centre on the town's history.