A GPS treasure hunt with your phone
Geocaching
Why locals love it
Geocaching.com directs you to the coordinates for geocaches (boxes of stuff) hidden all over the city (remember, if you take something, you need to leave something). The caches are hidden all over the city, and they can lead you to explore new neighbourhoods/parks. It's fun for people of all ages.
Why you should visit it
If you like walking around, but if you do not like walking around aimlessly, this is a great activity for you. It's fun. It's exciting. It can lead you to new places (and, sometimes, new friends). For more information, check out geocaching.com
Special tip
Remember not to take something from a cache without leaving something of a greater/equal value.