The amazing geology, archaeology, botany and wildlife of this North Mayo region is interpreted at the Céide Fields Visitor Centre, with the aid of an audio-visual presentation and exhibitions. The Centre, at Ballycastle, is an unusual part limestone, part peat-clad, pyramid-shaped building, with a glazed lantern apex, and was opened in 1993 by the Office of Public Works. It was joint winner of the inaugural Irish Building of the Year Award, organised by The Sunday Times with the Royal Institute of Architects of Ireland (RIAI). Céide Fields contain a 1,500 hectare archaeological site of stone walls, field systems, enclosures and tombs, dating from about 5,000 years ago, which have been preserved beneath the bog. It is the most extensive stone age site in the world. The wild flora of the bog is of international importance and is bounded by some of the most spectacular rock formations and cliffs in Ireland.