In the story, Wonderland is accessed by an underground passage, and Alice reaches it by traveling down a rabbit hole. While the location is apparently somewhere beneath Oxfordshire, Carroll does not specify how far down it is, and he has Alice speculate whether it is near the center of the Earth or even at the Antipodes.
The land itself is described as being heavily wooded and grows mushrooms. There are well-kept gardens and substantial houses, such as those of the Duchess and the White Rabbit. Wonderland has a seacoast, where the Mock Turtle lives.