CMOT TMPV wrote in message et...
Is there somewhere online I can find out which tube stations are underground
and which are above ground? Or if not online, somewhere I can buy a book
with that information. It seems like an easy request, but my research hasn't
got me very far.

This is strictly to the best of my knowledge and off the top of my
head! Corrections welcome...

O - Overground
U - In a cutting between and adjacent to two sections of 'Cut and
Cover' line (e.g. Bayswater).
C - 'Cut and Cover' (Or shallow excavation e.g. Hatton Cross)
T - 'Tube' (or deep excavation, e.g. North Greenwich)

Northern Line:
O Morden
T South Wimbledon - Charing X / Bank - Hampstead / Highgate
O Golders Green - Edgware
O East Finchley - Mill Hill East / High Barnet

Victoria Line
T All Stations

Waterloo And City Line
T Bank
C Waterloo (with one end open to Waterloo Depot)

Bakerloo Line
T Elephant & Castle - Kilburn Park
O Kilburn Park - Harrow & Wealdstone

Central Line
O West Ruislip / Ealing Broadway - White City
T Shepherds Bush - Bethnal Green
C Mile End
O Stratford - Snaresbrook - Epping / Newbury Park
T Wanstead - Gants Hill

Piccadilly Line
T Heathrow T4 & Heathrow T123
C Hatton Cross - Hounslow West
O Uxbridge / Hounslow Central - Barons Court
T Earls Court - Bounds Green
O Arnos Grove
C Southgate
O Oakwood & Cockfosters

Jubliee Line
O Stanmore - Finchley Road
T Swiss Cottage - North Greenwich / Charing Cross (Alright - CX not
strictly part of the Jubilee line anymore...)
O Canning Town - Stratford

Metropolitan
O Uxbridge / Watford / Amersham / Chesham - Finchley Road
U Baker St.
C Great Portland St. - Kings Cross St Pancras
O Farringdon
U Barbican
C Moorgate
U Liverpool St. & Aldgate

Hammersmith & City
O Hammersmith - Paddington
U Edgware Road
C Baker St.
[See Metropolitan]
[See District]

District Line
O Ealing Broadway / Richmond - West Kensington
O Wimbledon - Parsons Green
C Fulham Broadway (Only recently mind you!)
O West Brompton
U Earls court
C Glocester Road
U South Kensington - Sloane Square
C Victoria - Tower Hill
U Aldage East - Whitechapel
C Stepney Green - Bow Road
O Bromley By Bow - Upminster
U High St. Kensington - Edgware Road

Circle Line
[See Metropolitan]
[See District]

East London Line
O Shoreditch - Whitechapel
U Shadwell
C (T??) Wapping
C Rotherhithe - Canada Water
O Surrey Quays - New Cross / New Cross Gate.

Hope this helps!
Si.