Secret Garden (Create your own secret garden and describe the scene)
Design your own secret garden that is behind a hidden door. What would it look like? Your design can be as realistic or fantastical as you like (like the sweet garden in Willy Wonka's Chocolate Factory). What words would you use to explain to the reader what they can see, feel, hear, smell and touch).
Turn your plan into an opening paragraph for your story which sets the scene for where the book is set.