Long enough ago that the details are hazy, I read a short story in a sc-fi collection (from the 50s/60s) that had a plot with this in it:
Narrator’s friend buys property (I think maybe a bookstore, even). The backyard is filled with tall grass. Friend explores yard, almost gets lost. Insists to narrator that backyard’s dimensions shift, so that though it seems small, once you’re in it, it goes on forever. Eventually, friend disappears into backyard. Narrator goes to find him, gets lost himself. The story either ends with him lost or ends with him deciding to go back into the grass once more (with the implication that he will get well and truly lost, and also disappear).
Does this ring a bell with anyone? I did a few searches for it, and looked up story titles in “101 Great Science Fiction Stories,” which was where I thought I read it. None of those titles rang a bell, and further searches on the possible titles yielded nothing.
Anyone recognize it? Anyone?