Lexus Ltd, 2013.
This is an old, Scottish folk tale which is retold by Fiona Scott and illustrated by Elfreda Crehan.
"And there a small door, not noticed before ...".
If you want, you can read some of this book in Gaelic as well as English.
And there's a free mp3 recording of the Gaelic.
You can download it from Lexus for Languages