37down.Archaeological site on an inter-tidal sea stack on the NE coast of the isle of Lewis, near the village of Knockaird (3,7). The answer should be Dun Eistean but the 'a' clashes with a definite 'i' from an intersecting across answer. Is there an alternative spelling Dun Eiste I n or is there a compiler's error?
53ac.Pink Floyd's only Number one single in the UK.(7,5,2,3,4).The answer is 'Another brick in the wall. The I in 'in' is the letter that clashes with the 'a' in Eistean.