The Enchanted Castle by Edith Nesbit, Fiction, Fantasy & Magic

The three kids had to spend their summer vacation at a private school in the country -- but they didn't have to like it. They managed to sneak out onto the grounds, where they found a secret castle set in hidden parkland from a fairy tale. And the park is a maze with an enchantedly sleeping princess. . . .The lake, groves and marble statues, with white towers and turrets in the distance, make a fairy-tale setting, and then in the middle of the maze in the rose garden they find the sleeping fairy-tale princess.