Looking for ideas/activities to socialize as a group

Hello everyone,

With 3 other friends, we want to open our horizons, meet new people and try activities we never did before.
The concept is once a month, one of us is to propose a new activity he/she has never done before. Said activity must "force" us to socialize and can't be too expensive (~50€/person).

I'm reaching out here to harvest some ideas you nice folks could have!

For example, we already went to a comedy club & to visit a mushroom farm as part of a larger group.

We're all from the south of the country, but don't mind traveling a bit.

Any ideas ?