Berlin has several transit systems: the underground, or U-Bahn; the suburban railway, or S-Bahn; the trams; and the buses. We purchased a three day ticket at a U-Bahn station. It had to be validated before we first used it, but there after we could just use any train, tram or bus. No one looked at our tickets. Medical masks were compulsory on public transport, though not the stations, when I was there (August '22), and over 90% of people were complying. U-Bahn The U-Bahn was opened in 1902, and is the biggest in Germany. It is standard gauge, with power pickup from a third rail. Unlike the London Underground, the power rail is covered, with units collecting power from underneath the rail. There are ten lines, denoted U1 to U10. Many of the stations are simple island platforms, with steps straight down on to the platform, from the middle of the road. This is a larger, and more modern, station, Bundestag. I did not great images of the trains, but you can see two distinct styles; the