SOLVED. Children's fantasy or mystery: Child goes through a forgotten door in a church or possibly museum

[Shelley]

I read this book in the mid 1990s. I'm pretty sure the main character was a boy. He was walking home from school one day and for whatever reason went into (as I remember it) a huge church, found a hidden or forgotten door and ended up in a another place. It was a great adventure tale, and I think he also spoke to a priest there on a few occasions. He was able to go back and forth multiple times. The church was in a city, but I forget where he went when he went through the door.

I don't remember much else, but at the time, I remember the book seeming old to my 10 year old self. could have been printed anywhere from the 1930s-1970s as I went to an old school with an aged library.

[Shelley]

I just found a plot, and I believe it is Elidor by Alan Garner.

[Kris]

Shelley, I see your request is marked Solved. Glad you found your book.

Here are the Google Books previews:
- https://books.google.com/books?id=N3D... This preview has more text. There are different cover images.
- https://books.google.com/books?id=XFO... This preview has the Table of contents.