Is there such thing as 'musician pick-up playing' in the same way there are sports/games 'pick-up games'?

So if I want to go play (for example) basketball, or Magic the Gathering, or Poker etc. there are places I can go to find a game. I don't need a team or other people with me, I just need my own stuff to play e.g. trainers for sport, a deck of cards, money whatever. Other people also turn up and we can have some games.

Is there the equivalent for music? So I play guitar and I think it would be both fun and beneficial to my playing to play (jam?) with other people, but I don't want to be in a band. I just want to turn up, play some music with people who are of a similar skill level, or at least at a level I can contribute.

So does something like that exist? And what is it called? Bonus points for any place in the UK that is an example! Thanks