"D.M. Garner" wrote in message
...
When going East on the Jubilee Line from Westminster tube station
last night, I noticed a tunnel just outside the station, on the north
side, lit up and going downwards. It wasn't a train tunnel - it
went perpendicularly from the train tunnel, and had a square
cross-section. Does anyone know what this is?

Leads to a ventilation shaft which comes up on the pavement of Victoria
Embankment near Westminster Bridge. Nearly all the JLE stations have these
at both ends.