Amazonia: The Mysterious Cities of Gold

It is the 16th century. From all over Europe, great ships sail west to conquer the New World, the Americas. The men eager to seek their fortune, to find new adventures in new lands. They long to cross uncharted seas and discover unknown countries, to find secret gold on a mountain trail high in the Andes. They dream of following the path of the setting sun that leads to El Dorado and the Mysterious Cities of Gold. 

If you watch the intro (do it, do it now!), You'll notice that the title sequence starts in space. Theres a reason for that - the Olmecs (the bad-guys) are in fact a race of alien beings, who use solar energy to power super high-tech equipment, made out of gold, such as the eagle aircraft, to rule over South America, except they've forgotten it. or something, I can't quite remember.

Olmec:  Alien Mekon Types : Stat as Drow / Dark Elves

South American Alien pyramids sound vaguely familiar? Well it could be you remember the writings of Ancient Alien funky mojo proponent, Erich Von Daniken. Unable to believe that anyone who isn't a modern white European was able to do anything remotely significant in terms of culture or structural engineering, Von D jets around the world claiming every ancient structure bigger than a mud-hut was built by aliens.

Mexican Zigurats? aliens
Nasca lines? aliens
Egyptian pyramids? aliens
Stonehenge? aliens

Not only that, but all these ignorant people worshiped the aliens as gods....

No, Erich, God was not an astronaut.

Chariots of the Gods was first published in 1968. A film was made, with awesome music (tho' not up to Cities of Gold sing-a-long in a broom-cupboard level) and by the power of youtube you can watch it, it's fun romp with some killer imagery, as long as you remember it's as silly an idea as Uri Geller's spoonbending. I loved reading this stuff as a kid, aliens, exotic landscapes, unearthing ancient mysteries, the adventure and the hodgepodge of ancient art, so when the Mysterious Cities of Gold aired, I felt right at home.

And of course, this makes for cool D&D campaign background stuff. Hmm, prehistoric aliens with advanced technologies, leaving remnants of their ancient super-civilisation behind. Kinda reminds one of M A R Barkers Tekumel, where of course, the humans are the aliens. And I'm sure there is something Warhammerish about the idea...

John Blanche illustration | Slann | AD&D stat as Bullywugs

Oh yeah! A quick recap of the Warhammer 2nd Edition timeline, ice-planet, ruled by dinosaurs / dragons /lizardmen and a small population of human-like Amazons (see the Hammer fur bikini trilogy: One Million Years B.C. (1966) Prehostoric Women (1967) and When Dinosaurs Ruled The Earth (1970)) Warhammer worlds secret pulp-adventure origins... Then the alien Slann arrive, with names like Gotta-lotta-botl and Koppa-Ketl who proceeded to put warp-gates at the north and south pole for easy interstellar access, and begin terraforming the planet, and building pyramid-engines to stabalise the atmosphere and stuff.

Chariots of the Frogs | John Blanche Concept Art | Bullywugs

The Slann then genetically engineered various slave-races for different jobs,  " Eldest of all, the elf-children, Dwarf the delver, dark are his houses; Ent the earthborn, old as mountains; Man the mortal, master of horses" Oh no that's something else. Elves to psychically control things, Dwarves to build, Orcs to Waaaagh... Anyway, the frogmen created a world-spanning empire of genetic mutants, controlled the climate and battled with the Evil Forces of Skeletor Chaos spewing forth from their increasingly malfunctioning dimensional portals.

Alien Bullywug Overlords, 2nd compendium 1984 | Dave Andrews

Although, of course, by the time the adventurous westerners of the Old World in a fantasy version of the 16th Century, discovered the Slann on their steamy tropical continent of Lustria, their warp-gates had long-since collapsed, sending raw-chaos material into the world, their empire had crumbled, and they had decayed into barbaric tribal ways, haunting the jungles that had overgrown their once mighty city-states. The Slann had long lost all grasp of their ancient technology, although others, of course, had not entirely forgotten...