JR Yamanote Line
Great for orientation in the city
If you’re on your first trip to Tōkyō (or second or third!), a great wait to orientate yourself with this massive metropolis is to ride the JR Yamanote Line, a 34.5km loop line of 30 stations that takes about an hour to go around the central city.
I’d recommend giving yourself a couple of hours on your first day - go around once in one direction, then around again in the other direction! Keep your eyes open and look out the windows. It’s an absolutely fascinating trip - and of course, since it’s a loop, it doesn’t matter where you start.
Check out JR Yamanote Line for a list of stations and what they’re known for.
Of course, if you’ve got yourself a JR Pass or Tōkyō Day Pass, you can get on and off as much as you want.