Here is the 2nd largest city in Japan, in fact, you cannot really see the limit between Tokyo and Yokohama as they both grew so big that it is now a huge metropolis.
Door-to-door, it takes me an hour to go there. Many metro lines in Tokyo become suburb train lines and quite a few go to Yokohama, I usually take the Namboku metro line that continues to it.
Yokohama is know for
- the shopping malls
- the bay
- the amusement park in Minato Mirail
- the stadium for large events
It is closer to Haneda than Tokyo is for most areas.