In the early 90s, we lived in Florida, but my Dad ended up with a temporary part of his job with the federal government and had to live in Washington DC for about 14 months. Although, not full time. A week there, a week back in FL, back and forth. Although, that last month, he did have to stay about 4 weeks. At the time, the school system was trying out their year around school, which was kinda weird, but it benefitted us, as we could then go visit him a few times during that time, instead of just the summer.
Anyways, my Mom, me and brother ended up going by Amtrak train those few times, as it was cheaper that flying. It took about 17 hours to get there....although, myself being around 10 to 11 and very ADHD, wasn't so easy being stuck on the train that long, but looking back, it did give some good memories.
Then also, in Washington DC, they have their Metro (mostly underground subway system)
I always liked the sound it made, and just found this cool audio ambience someone recorded from it.
I also liked how they made the roof of each station like this.