I don’t have a great head for heights. In fact, the midway rung on a loft ladder or the crook of an apple tree is as high as I usually like to climb. So, what were we doing following the track to the dizzying tops of Bempton Cliffs, which rise a thousand feet above the North Sea? We were lured by the idea of visiting Yorkshire’s “seabird city”. RSPB Bempton Cliffs is home to half a million nesting gannets, razorbills, guillemots and puffins.