YA book (or series) about a miniature world in the attic (and entering that world) [s]

[Louis]

in this book (or series), the children were able to enter a miniature world contained perhaps in a toy set of some kind located in their attic. they did this by using a Janus headed coin: one side shrunk them and put them into the world, and the other side got them out (maybe?). in the world, there was magic (i believe they could use magic) and they may have fought each other at one point.

i specifically remember the Janus coin... not much else. i would have read this book sometime between 1994 and 2000.

[Alyssa (The Shady Glade)]

Is it The Castle in the Attic? I haven't read it myself, but your description made me think of this one first.

[Louis]

yes!

[Alyssa (The Shady Glade)]

Oh good, I'm glad that's it. Like I said, I never actually read it, but I picked it up at the library many times. I just never made it all the way to checkout without putting it back. Too many books, so little time...

[Ka]

oh, dammit! Someone already said it! And here I was so excited I could help for once. Loved this book when I was a kid. <3 (The sequel is good too, but I don't recall liking it as much.)