Related Clues:
- Den focus, familiarly
- London transport, with 'the'
- Pipette, e.g
- Word with "inner" or "test"
- It includes Piccadilly and Victoria lines
- London Underground
- Pack of toothpaste; type of train
- Channel four rock/pop show once fronted by Jools Holland
- Transport system bringing objection around England's capital?
- Long hollow cylinder
- Train and boat, heading for Europe
- Valve container, earliest bit of electronics
- Underground; pipe
- Pipe; underground train
- Billions invested in weekday train network