The Spaniards who explored the Americas in the 16th century had one basic aim in mind, which was to become enormously wealthy by discovering and claiming the vast hordes of gold that they were quite convinced lay in the lands across the sea.
The legend of Antillia
One legend that was widely believed was that when the Moors invaded Spain in the 12th century seven bishops and their followers escaped and sailed to the west. They had found a new land to settle and each bishop had established a city-state that had grown rich and magnificent. The land was supposed to be an island called Antillia.
The belief in Antillia was so ingrained that maps of the time actually depicted it, and this was somewhere that Christopher Columbus expected to visit as a stopover en route to the Indies. There was even a legend that a ship had landed there and found that the beaches comprised only one-third sand, the rest being gold dust!
Needless to say, the early explorers did not discover the Seven Cities of Gold on Antillia, although the islands of the Caribbean were named the Antilles. However, this did not kill the legend. The cities must therefore be somewhere else, according to the Spanish.
In 1528 an expedition into the interior of North America brought back stories that the natives lived in fabulously wealthy cities, seven in number, of which the greatest was called Cibola. This was all that was needed to get the Spaniards excited and a new expedition was organized with a view to finding the Seven Cities of Cibola and plundering their riches.
This was led by Don Francisco Vasquez de Coronado, who failed in his aim but did achieve something that no European had done before, which was to view the Grand Canyon.
So what were the seven cities?
It has to be assumed that what the early explorers had discovered were the pueblos of the Zunis and other tribes in what is now New Mexico and Arizona. These were structures built largely from adobe mud. Many of these buildings were multi-roomed and on more than one storey. A notable feature was the method of entering buildings from the roof via a ladder. Many such structures were grouped around courtyards. The communities were home to hundreds of people.
<a href="https://en.wikipedia.org/wiki/Taos_Pueblo,_New_Mexico" target="_blank" rel="noopener">Source</a>
The pueblos certainly counted as cities, but why golden? That might well be explained by the fact that straw was often mixed with the mud to help to bind it, and sunlight glinting on straw might look like gold from a distance.
So did the explorers leave well alone and go home disappointed? Not exactly. The Pueblo Peoples, like the rest of the Native American population, would soon find to their cost that Europeans sought only conquest, not cooperation.