What are group exercise activities that are appropriate for a variety of fitness levels?

I will always say walking, any form of it. Walking is such a good way to be active in an easy manner. You can walk slowly, you can walk fast, you can hike. There are many ways to walk like a walk in a park or to go walking in a beautiful place or walk in a mall. A wide range of fitness levels are good to walk and walking is a great group activity.