A "beautiful, fertile valley"—nestled "in the midst of a barren wilderness area" somewhere in the United States, and sequestered from the outside world by an encircling curtain of towering cliff—which is inhabited by "a lost colony of Quakers," descendants of a Quaker colony of the eighteenth century whose members "roamed the forests and mountains" of America in search of a refuge from the "world of evil, greed, and war" around them, until finally they settled in the "vast, fertile crater" known as Crater Valley, retaining their simple customs, clothing, and manner of speech and doggedly protecting their children and grandchildren from the temptations of the so-called "world beyond" by teaching them that "only barren wastes" lay beyond the valley's cliffs and that all human life on Earth resided within the boundaries of their lush, green valley. Of all the modern-day inhabitants of Crater Valley, only Peter Fry, and later Luke Robb, know that human life and civilization exist in the world beyond the valley.
Literally plummeting into the valley in May 1965 after accidentally falling out of the gondola of an observation balloon sent aloft to enable reporters to witness the launching of an experimental American space rocket, Clark Kent soon makes the acquaintance of Peter Fry and his lovely niece Elizabelle and, at Fry's urging, accepts the job of village blacksmith in the old-fashioned Quaker community—one of several such communities in the valley—where Fry himself resides.
As the days pass, Kent develops a special affection for Crater Valley and its people, and the valley becomes for him a special haven where, even in his Clark Kent identity, he can abandon his role of cowardice and timidity and be a man of strength and courage.
"It's refreshing to be admired for my strength for once instead of being scorned for my timidity!" muses Kent at one point. And later he thinks, "...I'm not ready to leave this valley. It's the one place in the world where I can live as Clark Kent, without posing as a cringing coward!"
During his brief sojourn in the valley, Clark Kent enjoys the admiration of his neighbors and the lovely Elizabelle; defeats and then befriends a gruff, sometimes bullyish fellow named Luke Robb; and uses his super-powers to save Peter Fry from a potentially fatal bout of fever before soaring out of the valley as Superman to resume his normal life as a super-hero in Metropolis.
"...I'll come back some day," thinks Superman, as he flies over the top of the valley's cliffs. "This valley will make me a peaceful haven for me. Whenever I'm tired of my meek, Clark Kent identity, I'll return to the one spot on Earth where Clark Kent can act like a he-man" (Act No. 324/1: "The Secret Life of Clark Kent!"). (TGSB)