For centuries, the north of Ireland has attracted visitors eager to see for themselves some of the most splendid natural scenery in the world. The Giant's Causeway, the Mountains of Mourne, the Glens of Antrim, the Fermanagh Lakeland... Lovely as these landscapes are from ground level, their impact from the air is truly breathtaking. Everything is intensified - the famous green of the fields, the inviting sweep of the beaches, the majesty of moorland and mountain, the silver of rivers and waterways. Here are 134 of the best photographs by leading Irish photographer Esler Crawford...