Beyond the backyard of Calvin's house is an area of woodland which probably expands over about 15 acres. Some of this area was destroyed when part of the forest was clear-cut to make way for a condominium development, "Shady Acres".
From time to time, Calvin goes walking or hiking in the woods along with Hobbes, discussing topics such as current events, life, or even about how things are going for him. In the Tenth Anniversary Edition, Watterson remarks: "The solitude of the woods brings out Calvin's small, but redeeming, contemplative side."
Calvin passed through the woods on his way to the Yukon Territory; as Calvin lives south of Canada, the forest would be north of his house.
The woods have widely spaced trees, many hills and paths, and several conveniently placed cliffs, creeks, ponds, clearings, and bramble patches.
There is also a creek in the woods, called Hobbes Creek.
Although some conifers are occasionally seen, the woods seem to contain mostly deciduous trees. There are also raccoons present. In the creek, there are turtles and fish.
There are cliffs in the Woods where Calvin and Hobbes pilot their wagon, sled, or toboggan. Once, Calvin glued several colored feathers to his shirt and sprinted of the cliff. After hovering for less than a second, he crashed into the base of the cliff. That was the first and last known time Calvin tried to fly off the cliff. Another time, Calvin and Hobbes tried to time warp into the future by racing down the hill. As Hobbes looked around and saw there were no flying cars he was unimpressed. However, Calvin glanced at his watch he gleefully explained to Hobbes that it was a whole two minutes after they started. On another occasion, Calvin and Hobbes tried a similar experiment, testing out Einstein's theory that if one were to travel fast enough, time would actually stop. Calvin lost control and the pair fell into a ravine. Calvin decided that Einstein was probably a fraud, but Hobbes noticed that his watch had stopped (on impact) and declared Einstein to be correct.
Calvin and Hobbes also have encountered many of the lakes at the bottom of the cliff. Which could also mean that there is more than one cliff.