It depends a lot on the city in which you happen to live. Baltimore, for example, has a great deal to offer in the department of bosque, bower, glade, and verge - this, for example, was yesterday evening, halfway up a very tall hill that happened to be part of my route home du jour: http://i.imgur.com/84Q2mxu.jpg

(That said, you wouldn't catch me barefoot in any woods around here - for all that I grew up that way, the woods back home are not noted for their likelihood of putting broken glass or old masonry underfoot, while those around here are full of such things.)

Barefoot or no, it's definitely worth making the opportunity, if there's a way you can do so! On the other hand, if there are no handy woods nearby, there's a great deal to be said for making the most of the environment you find to hand. No matter where you happen to be - there are wonders all around you, just waiting to be found.