If you want a hobby that will keep you fit and that you can do in Greece too then swimming is pretty good. No need to invest in expensive equipment, just some shorts and goggles. It has so many benefits, off the top of my head it's low impact, good at burning calories, you don't get hot and sweaty, it'll add muscle if done right and also massively improve your fitness. The only downside is that it makes you super hungry but if you eat good healthy food it won't be a problem.
I used to go a few times a week when I was younger and want to start again as I enjoy it so much. I went for the first time in ages last night and I feel so much better for it today, my analogy is that it's like going for a blast in an older car with carbs, opening up the throttle clears all the crap out and the car runs better afterward.