he journey up Lough Foyle to the ancient walled city of Derry, in Ireland's scenic North West Region, represents a Celtic voyage in miniature.

In Celtic mythology, Lough Foyle was one of the entrances to the kingdom of the sea god Manannan mac Lir, while the white waves on the sandbanks, or "Tuns", which lie just outside the entrance to the Lough, were believed to be Manannan's cavalry.

On the western shore of Lough Foyle are the picturesque fishing villages of Moville and Greencastle where the ruined Norman fort built by Richard de Burgo in 1305 can still be seen. On the opposite shore, is the distinctive flat-topped Benevenagh hill where, according to legend, St Columba converted Mongan, the reincarnation of Manannan the sea god, to Christianity. Columba or Colmcille was one of the key figures of medieval Irish monasticism and among the most important monasteries founded either by Columba himself, or his followers, were Derry, Iona, Swords end Durrow.

Mussenden Temple, one of Ireland's most famous architecturalfollies stands nearby, poised precariously at the edge of Downhill.

Modelled on Italy's Temple of Vesta, the Mussenden Temple was built two hundered years ago by the Earl Bishop, Federick Harvey.

Six mile upstream from where Lough Foyle becomes the River Foyle, stands Derry, Ireland's last remaining walled city which was developed by the Trade Guilds of London in the early 17th century and renamed Londonderry.

Derry's Celtic origins resonate in its name - Daire is the Gaelic for oakgrove, the oak being laden with symbolism for Celtic people throughout Europe.

Evidence of the Celtic riches yielded by the land around Lough Foyle can be seen in Derry's multi award-winning Tower Museum which, uniquely, has been named both Irish and British Museum of the Year.

The walls of Derry embrace an historic city centre with a number of fine buildings including St Columb's Cathedral (1633) which played an important part in the city's Great Siege of 1689.

Just over four miles from Derry, another hilltop fortification, the mystical Grianan of Aileach, dominates the landscape. This round fort dates from about the 6th century AD but lies at the centre of a complex of Stone-Age monuments.

From Celtic crosses like the Donagh Cross in Carndonagh to the Celtic motifs which characterise the local crafts and folk music, the North West's Celtic heritage remains a vibrant cultural force throughout the region.