I am trying to locate a sci-fi book that I read in my teens, something like 65 years ago! That would have been in the 1950s; I was born in 1943 and became an avid sci-fi reader when I was about 15.
I don’t recall the title of the novel, nor any details about the plot. The setting was the Yucatan, and the plot a sci-fi adventure based on the myth of Quetzalcoatl and aliens. Which is precious little to go on. But I thought it worth asking.
Might this be Find the Feathered Serpent by Evan Hunter (Ed McBain)...?
It is a sci-fi novel, first published 1952. The story is based on the mythical Quetzalcoatl. And it is set mostly in the Yucatan.
When the strange hourglass-shaped time machine crashed out of the twentieth century and into the Caribbean Sea of fourteen hundred years ago, Neil Falsen realized how unprepared he was to head the expedition that his father had organized back through time. Of the four men who had flown through centuries to solve the mystery of an ancient Mayan god, two had died in the shattering crash. Only Neil and ship's pilot Dave remained to cope with the language and customs of a people who had disappeared into the darkness of history.
It was confusing enough not to know which century the machine had fallen into. But Neil was sure his eyes were playing tricks when he spotted a Norse ship cutting proudly through southern seas. How ancient Vikings, Mayas and two twentieth-century Americans met - and fought - amid the splendors of a civilization that today dots the Yucatan peninsula of Mexico with its ruins, makes a tale as unique in telling as it is in content.
In scenes that throb with drama and thunder with excitement, Dave and Neil found frightening evidence of the approaching Mayan collapse. With a common modern device, Neil stepped into a tense religious ceremony to prevent human sacrifice. Without realizing it, he discovered the secret of the white god among the Mayan Indian deities. One of history's most intriguing suppositions forms the basis for this tale of the secret behind the legend of a lost civilization.
Tom Swift and His Electronic Retroscope by "Victor Appleton II", 1959.
Set in the Yucatan, features a device to read ancient worn stone carvings, left by some aliens that Tom is in contact with. Ironically, this technology is now possible.
It's got Mayans, and the usual sorts of bad guys.
I just reread this a couple months ago. Can't really recommend doing that. Hard to believe how much I liked this kind of thing 60 years ago.
It isn't set in the Yucatan, it's in the Mexico city area, but this could be Clash of the Star Kings by Avram Davidson. This was published in 1966 so you could have read it 55 years ago. It was nominated for a Nebula so it was quite a well known book at the time.
The Aztec gods turn out to be aliens who arrived in the distant past. The book is set in contemporary times (i.e. in 1966) and the plot is that one faction of the aliens now want to take over the whole Earth:
On one side, the Great Old Ones, who had benevolently ruled the land in the days of the Toltecs, before the coming of the cruel Aztecs.
On the other side, the Huitzili, who had come from the distant Evil Stars to teach the Aztecs conquest and war. In return, they demanded endless human sacrifice, human blood, and human hearts. And now, if they gain control of the awesome secret power within the mountain, they will plunge the entire Earth into endless barbarism!
Quetzalcoatl is mentioned, though the story isn't specifically about that god.
I know the question specifies a novel, but the Henry Kuttner short story "Or Else" was published in 1953, and involves an alien who is called (by the protagonist) Quetzalcoatl. Readable at archive.org.
The stranger's nostrils pinched together slightly, but he ignored the remark. "I come from another world," he said. "My name is —" In Miguel's mind it sounded like Quetzalcoatl.
"Quetzalcoatl?" Miguel repeated, with fine irony. "Oh, I have no doubt of that. And mine is Saint Peter, who has the keys to Heaven."
This story takes place in Mexico. It doesn't specify location more closely than that.
The steel blazed in the hot Mexican sun.
