On Fri, 23 Nov 2007 20:26:59 GMT, Richard J. wrote:

As Innes Ferguson, TFL design director said at the LT Museum on
24/9/7, the "Overground" brand made [sense] since as "you
wouldn't expect to see 'Underground' on a roundel outside a
station in Brighton".

Nor would you at Amersham, 147 m (490 ft) above sea level, but people
seem to have accepted it for many years.

?

It was an example of a station with surface-level platforms so far above sea
level that that being on the "Underground" is arguably more bizarre than
Brighton being similarly branded.

Where does sea level come into it? Surely "underground" just means
below ground level, regardless of how far that is above (or indeed
below) sea level.