Now now, Gef, let's not get facetious! According to sddsddean, Barr Beacon (what is it, by the way?) is 17.5km higher than Ben Nevis, even though Ben Nevis is taller because of the curvature of the Earth.
If you read my first answer you will see that Barr Beacon is 227 metres high. It is a small hill in the Birmingham area. To claim that it is 17.5 km higher than Ben Nevis makes me laugh. It would be the highest mountain in the world - and most of it would be in outer space!