From where you spend most of your time,
Leave the building and face east.
Now, walk as directly east as possible.
Spend 15 minutes walking east, without using your phone to guide you or checking time.
Make observations of what you see around you.
If you see anything interesting, spend as much time as you want investigating.
We spend so much of our time walking along the same routes, we forget to stop and explore the area around us.
Walking in a direction, rather than with a destination in mind, forces us to look up and around, and gives us time to take in some of the things we might normally ignore, because we take a more optimal route.