Take a Hike in the Urban Jungle (video)
But if you're not one to venture into the woods, you can explore your city in the same fashion. It's a nice, green way to spend a lazy afternoon.
This great little video shows what kind of discoveries you might make during an Urban Ramble. It reminds me of the Family Circus cartoons where Billy rambles all over his neighbourhood (pictured)
(Source: Do The Green Thing)