Wonderland is Alice's own world as a place where nothing is as it is supposed to be and everyone is what they aren't supposed to be. Wonderland is shown to be home to many unusual creatures, such as talking flowers and insane animals. One thing to note is that the local food and drink seem to have unusual effects on humans. In Wonderland, everything that Alice eats or drinks causes her to change sizes. The vast majority of Wonderland is forested, though there are other areas such as a shoreline and a meadow of flowers. Wonderland is shown to be ruled by the Queen of Hearts and her diminutive husband, the King of Hearts.
In the film, a beautiful young woman called Alice falls through a mysterious rabbit hole, which eventually leads her to the world of Wonderland. Alice's curiosity leads her to search for the White Rabbit, whom she had followed down the hole, as she wishes to know where he is going. She also wishes to find her way back home. Along her journey, she traverses the unusual world and meets its even more unusual inhabitants. However, in the end, it is revealed to her that the world only exists in her dreams and she is able to escape once her sister wakes her up.
Wonderland can be visited from Fairytale Land via the Portal of Doors in Jefferson's hat. Queen Regina convinces Jefferson to take her there to retrieve something from the Queen of Hearts. After successfully retrieving a box from a vault belonging to the Queen of Hearts, the Evil Queen takes a piece of the Caterpillar's mushroom and places it in the box, causing her father to appear. Per the rules of his hat (which dictate that only the same number of people can exit the Portal of Doors as entered), Jefferson is unable to leave Wonderland. He is brought before the Queen of Hearts and tasked with making another magical hat. This is strongly implied to be the cause of the Mad Hatter's "madness;" his inability to create another hat to get home to his daughter. It is later revealed that Cora, the Evil Queen's mother, is the Queen of Hearts. It is known the Queen pushed her through an enchanted looking glass that brought her to Wonderland. Still, it's unknown how she became Queen there. Wonderland also seems to be a world hated by most people in the Enchanted forest, probably because of its lack of logic. When Regina asks Rumplestiltskin for help with her mother, he tells her he can send Cora to an "Annoying Little World". Also, when Jefferson and Regina visit this world, once they meet the caterpillar and he smokes in their face, Jefferson says "I Hate Wonderland".