The Chronicles of Narnia: The Lion, the Witch and the Wardrobe (2005) on Netflix

During the German air raids of WWII, the four Pevensie children - Peter, Susan, Edmund and Lucy - are sent out of London to take shelter at the country home of eccentric Prof. Digory Kirke, who happens to be the owner of a curious wardrobe. Peering into this wardrobe one day while playing "hide and seek", Lucy finds herself in the snowy land of Narnia, which is mired in never-ending winter thanks to the magic of the evil White Witch, who has proclaimed that it will be always winter but never Christmas in the mystical land. Eventually, the other Pevensies find themselves in Narnia, and the four children learn that they alone are the key to breaking the Witch's eternal winter. But while three of them trudge through the snow with some helpful Beavers to join forces with Aslan, the mighty Lion, the fourth takes a more treacherous path and falls in league with the Witch...