From Webkinz Insider Wiki
Webkinz woods is an area of Webkinz World that has been revealed in the W-Tales stories.
In An Air of Mystery Book, Doug and Sparky ride through Webkinz woods to get to Mount Kinz. The story states that they rode through Webkinz woods for hours on their bikes, suggesting that Webkinz woods covers a very large area.
The trees of Webkinz woods are visible in the distance in the Outside Yards.