If animals are a possibility, I would include horses and maybe like fostering dogs or agility with dogs. I found refuge in the barn with horses and in working with animals.
Other options - hiking, rowing as others have mentioned (there is team and individual with rowing - and a single can be quite meditative). I am hoping when the kids are older that we will be able to do hikes like the Grand Canyon and other national parks. I believe you are in Europe so I am wondering if there are places like that to look forward to. I know when we stayed in Toscana, one of our favorite activities was walking on the trails by our hotel in the countryside. My parents have always been big on walking (like they would park a mile or two from city center and then we would walk in) and that has stuck with me today where I prefer to walk when possible. Could that be something that you can encourage as a family?