The secret garden.

She put her hands under the leaves and began to pull and push them aside. Thick as the ivy hung, it nearly all was a loose and swinging curtain, though some had crept over wood and iron. Mary's heart began to thump and her hands to shake a little in her delight and excitement. The robin kept singing and twittering away and tilting his head on one side, as if he were as excited as she was. What was this under her hands which  was square and made of iron and which her fingers found a hole in?It was the lock of the door which had been closed ten years and she put her hand in her pocket, drew out the key and found it fitted the keyhole. She put the key in and turned it. It took two hands to do it, but it did turn.
And then she took a long breath and looked behind her up the long walk to see if any one was coming. No one was coming. No one ever did come, it seemed, and she took another long breath, because she could not help it, and she held back the swinging curtain of ivy and pushed back the door which opened slowly—slowly.
Then she slipped through it, and shut it behind her, and stood with her back against it, looking about her and breathing quite fast with excitement, and wonder, and delight.
She was standing inside the secret garden.
( The Secret Garden by Frances Hodgson Burnett)