The Marion E. Wade Center of Wheaton College, Illinois is a major research collection of materials by and about seven British authors: Owen Barfield, G.K. Chesterton, C.S. Lewis, George MacDonald, Dorothy L. Sayers, J.R.R. Tolkien, and Charles Williams.
Learn more on their website.
The are located on the west side of Washington Street (across from Edman Chapel parking lot).