An example of superstition among the villagers comes when an old man warns a young man just as he's about to throw a pebble into the giant hole. He tells the young man that his actions might bring a curse on the village. His rationale seems to be that the hole has appeared on sacred ground—where the recently-destroyed shrine used to stand before it was swept away by a typhoon.
The old man, therefore, regards it as sacrilegious for the young man to start throwing pebbles and other objects down the hole. The best thing to do would be to leave it alone or perhaps build a new shrine over it.
As it turns out, the old man's intuition appears to have been correct as, at the end of the story, the former village—now a thriving modern city—is about to plagued by the return of all the many hundreds and thousands of objects that were dumped into the hole over so many years: a plague that, like a biblical pestilence, will descend from the sky.