As I've written about before, I'm a fan of writing letters. I have one steady pen pal and another occasional one. I used to have one in Bamako, Mali (West Africa) but we lost touch; when I was a kid we served as a host family a couple times for her when she visited the States. I've been sending letters since I was 11.
My latest pen pal experience though is through UNESCO. Earlier this year they launched the PenPal network, open to writers, publishers, librarians, etc. who live in a designated UNESCO City of Literature (Seattle became one in 2017). To date, there are 42 cities around the world that are official Cities of Literature. There are many you'll recognize (Dublin, Barcelona, Milan, Prague) and then others that you might not (Tartu, Slemani, Kuhmo, Ulyanovsk).
I applied to the program and was accepted. I was assigned a pen pal in Melbourne, Australia who seemed very nice, but she bailed on the program. So then I was matched with a new pen pal near Iowa City, IA—the only other American city on the list besides Seattle. She also seems very nice. We haven't written yet but met on Zoom (another feature of UNESCO's program). It would be lovely if we got an opportunity to meet in person one day.
Letter writing is not obsolete, but far less common in our digital age. I hope programs like this persist.