[jeffbr13]

Berlin's U/S-Bahns certainly give the impression of being open 24/7 -- I've never had problems getting to/from clubs or airports at any time of day.

London can also claim a useful 24/7 service, with the night tube starting a couple months ago and the third and fourth lines (Jubilee and Northern) just opening up this week[1].

[1]: https://tfl.gov.uk/campaign/tube-improvements/what-we-are-do...

[mrec]

London's Night Tube only runs on Friday and Saturday nights, which I'd think makes it 24/2 rather than 24/7.

[douche]

It's been a few years, but I remember getting stranded at the U-Bahn station a few times when I was in college because we got out of the bar too late and having to walk home or wait around for daylight.

[tormeh]

It's open 24 hours on weekends but close at nights preceeding working days.