Turn the walk into a HIIT workout. Run 200 meters, then do pushups, then run, then do squats. Find an area where you can incorporate other options like pull-ups or plank.

Learn parkour. Incorporate parkour into the walks to cut between areas, jump between walls and buildings, etc.

Make a sketch of some object you find intriguing. A plant, a house, a pile of trash. Just try to spot something to sketch every time you go out for a walk

Incorporate trespassing into your walk. Through a back yard, a private corporate area, mix it up.

Spot someone who is already out for a walk. Follow them at a distance back to their destination. But don't get noticed!

Make a meal for an elderly person in the neighborhood and walk it over to their house.

Go on lesser-known trails. Non summiting trails and through-trails.

Plant some native plants in public spaces around the neighborhood. During your walks, so tend to these plants. Care for them.

Start making a map. Every time you go out on a walk, you add more area or detail to the map.