A helicopter crew films ancient marks man has made on the Irish landscape.

Early agricultural work, mysterious megaliths and religious settlements are captured by an air-borne camera in this third episode of the series ‘The Lie of the Land’ which examines the geological, archaeological, industrial and social aspects of Ireland.

Stone was the building material used along the exposed coasts of Ireland’s southwest Atlantic coast. This is exemplified by the Iron age fort on a rocky promontory at Dunbeg, just south of Slea Head on the Dingle Peninsula in County Kerry. Less adventurous folk chose to live inland in simple earth forts or raths such as Donard rath in County Wicklow. Raths were characteristic dwellings of the well-to-do in the period AD 500 - AD 1000.

With the arrival of Christianity in the fourth and fifth centuries, fundamental changes took place in Ireland. The exact arrival of Saint Patrick is uncertain and some doubt his existence entirely believing him to be a combination of missionaries conflated into one saint. His tradition is strongest in the north-east of Ireland and he is said to have herded pigs on Slemish mountain in County Antrim.

A simple localised beginning for a national apostle.

According to legend Saint Patrick built his first church at Saul in County Down. The present church at Saul emphasises the myth as it is a Victorian pastiche mimicking ancient architecture, emphasising the Christian continuity of the place.

Modern memory pays reverence to ancient events.

Legend also says Patrick celebrated Easter on the Hill of Slane in County Meath, nine miles from the Hill of Tara, the seat of the High King of Ireland.

In the west the mountain that bears Patrick’s name is Croagh Patrick in County Mayo, and the track to the summit oratory remains an important pilgrimage route. This hilltop walk undertaken by devotees mimics that formally performed on the hilltops for the Celtic sun god Lugh.

'The Lie of the Land: The Ancient Landscape' was broadcast on 14 February 1982. The narrator is Jonathan Ryan.