Sci-fi story about tunnel in wall that leads to the same location

Question

I'm looking for the name of a short sci-fi story about a town located near a massive, seemingly endless wall. When the inhabitants find a hole in the wall, they send a man in to investigate what's on the other side. When the man reaches the other side, he's flabbergasted at finding out he's reached the same location, being greeted by the same townsfolk he left behind.

Update: The story was similar to J.G. Ballard's "The Concentration City" or "What Dead Men Tell" by Theodore Sturgeon, in that the protagonist discovers that, if one kept traveling forward, one finally ended back in the same place (Wormhole/Möbius Strip/Space-time distortion kind of phenomenon). One additional detail I remembered is that at one point, when the protagonist is going through the tunnel in the wall, he sees the light at the point where he entered moving farther away the more he advanced, beginning to see light at the opposite direction up ahead (meaning he simultaneously could see both entrance and exit at one point). But when he reached the end, it was the same entry point where he had waved goodbye to the townsfolk. The story didn't include intricate plot points of any sort, only a town surrounded by this immense wall, a man entering through a newly-discovered crack/crevice/hole in the wall, going through a tunnel-like passageway, then exiting the same way he came, being asked by the townsfolk (who think he returned) what he saw, much to his shock.

These stories contain similar elements to the one I'm looking for: "The Concentration City" by J.G. Ballard. "What Dead Men Tell" by Theodore Sturgeon. "The Wall of Darkness" by Arthur C. Clarke. "The Wall Around the World" by Theodore R. Cogswell. "The Tunnel Under the World" by Frederik Pohl. "The Tunnel in the Sky" by Robert Heinlein. "The Long Wall/Settler's Wall" by W. O. Morley (R. A. W. Lowndes). "The Pen and the Dark" by Colin Kapp. "The People on the Precipice" by Ian Watson. "On" by Adam Roberts. "Escapement" (Clockwork Earth #2) by Jay Lake. "Stone and Sky" (The Stone Trilogy #1) by Graham Edwards. "Kingdoms of the Wall" by Robert Silverberg. "Stardust" by Neil Gaiman. "The Tunnel Ahead" by Alice Glasser. "The Wall at the Edge of the World" by Jim Aikin.

These don't have similar plot elements, but the titles can be misleading, listed here for clarification: "The Crack in the Wall" by Walter Jarvis. "The Great Wall" by Wayne Wightman. "The Other Side of the Wall" by Stanley Ellin.

Answer 1

after much researching and nearly driving myself insane with this story search, I have come to the conclusion that it must have been "The Wall of Darkness" by Clarke. All the details coincide, except for the tunnel/crack in the wall, and the townsfolk asking him at the end what he saw. Perhaps, I have mixed stories, and my fading memory didn't help. For now, I am placing "The Wall of Darkness" as the correct answer, since it's the story that most resembles mine and I have found absolutely no trace of the other one, which should've probably popped up by now. Many thanks to all who answered and considered this. Should I by some crazy chance ever happen to find one similar to the one I described initially, I shall post it as an update.

Answer 2

It's been a long time coming, but I seemed to have found the story after all!!!

I may have indeed taken elements from "The Wall of Darkness" and other stories and mixed them up. But the story I was actually looking for was "The Long Wall" by Wilfred Owen Morley (Robert A. W. Lowndes) all along!! I initially listed it above as not being it, but I recently re-read it and was so surprised to find it actually was, all the details were there. The story was published in "Stirring Science Stories - March 1942".

You can read the story in the original publication here:

https://archive.org/details/Stirring_Science_Stories_v02n01_1942-03

Or read just the story online here:

https://en.m.wikisource.org/wiki/Stirring_Science_Stories/March_1942/The_Long_Wall

This is the line I remembered regarding the light source, which was similar to "The Wall of Darkness":

"The only thing he would tell them was that he dropped the flashlight and it went out, but the light kept on going. He could see the shaft of light from the extinguished flash drifting slowly away into the unending blackness, a shaft of it etched against utter black."

And also this one: "And sometimes he awakes in a cold sweat, gasping about a shaft of light drifting away into utter blackness, drifting away from its source: an extinguished handlamp." ​ This light source moment, when the protagonist realizes there is some spatial anomaly phenomena at work, is similar to "The Wall of Darkness" too.

Same applies to the characters being baffled when they go opposite ways from their starting point in the wall, but end up meeting each other again as if they had gone in a circle.

Another detail I would like to add is that I may have also read other stories about endless walls in a more fantasy/medieval type of setting, since I actually started to remember the townspeople being medieval, not alien or contemporary human civilizations, definitely not from contemporary Maine. So maybe I also mixed it up with stories like "The People on the Precipice" by Ian Waston? Or "The Wall Around the World" by Theodore Cogswell, even.

Regardless, I'm very positive this is the explanation; this story, along with other stories I might've read, formed a nebulous memory and I amalgamated them all into one single story. But this one looks like it's pretty much it: features a wall that's always been there but people have learned not to question; baffled protagonists trying to solve the mystery; a hole in the wall the protagonist goes into with a light source; and the protagonist emerging from the same way he went in, to everyone's bewilderment.

I'm so glad I finally found this story, which was driving me insane! Once again, thanks to everyone who replied and took the time and effort to research this as well! Hope y'all enjoy the story!