The Galapagos Islands were officially discovered in 1535 by the Spaniard Tomás de Berlanga, by then the Bishop of Panama. But they could have been known much earlier. Or, at least, that's what the legends say.

The Spanish conquistador Pedro Sarmiento de Gamboa dealt with the matter in his Historia de los Incas (Historia Índica II, 1572).

While Topa Inga Yupanqui was conquering the coast of Manta and the islands of Puna and Túmbez [present-day Ecuador], some merchants arrived there who had come by sea from the west on rafts with sails. They informed of the land from which they came, which were some islands, one called Auachumbi and the other Niñachumbe, where there were many people and gold. And as Topa Inga was of high spirits and thoughts and was not content with what he had conquered on land, he decided to try that happy, inviting adventure by sea.

But he did not lightly believe the seafaring merchants, since he used to say that the capacs [chiefs, authorities] should not believe merchants so easily, because they were people who talked a lot. And to obtain more information, and since it was not a business that he could be reported about anywhere, he called a man he brought with him on his conquests, called Antarqui, who was known to be a great necromancer, so much so that he flew through the air. To him, Topa Inga asked if what the seafarers said about the islands was true. After having thought it over, Antarqui replied that what they said was true, and that he would go there first. And so they say that he went by his arts, and he checked the way and saw the islands, people and riches of them, and when returned he gave assurance of everything to Topa Inga.

Who, with this certainty, decided to go there. And for this he made a very big number of rafts, in which he embarked more than twenty thousand chosen soldiers. Topa Inga sailed and went and discovered the Auachumbi and Ninachumbi islands, and returned from there, bringing black people and a lot of gold and a brass chair and a horse's hide and jaws. These trophies were kept in the fortress of Cuzco until the time of the Spaniards. This horse's hide and jawbone was kept by a principal Inga, who lives today and provided this story, and when the others were ratified, he was present, and his name is Urco Guaranga.

Hahuachumbi ("outer island") and Ninachumbi ("island of fire") also appear in the accounts of the Hispanic chronicler Miguel Cabello Balboa (Miscelánea Antártica, ca. 1586) and the Mercedarian friar Martín de Murúa (Historia General del Perú, ca. 1616). The first points out, in chapter XVII:

...and conquering and dominating those untamed nations, he was able to reach the valley of Xipixapa, and from there to Apelope, and Topa Ynga learned that very close to that point there was a good port to navigate, and see if there was any enterprise in the sea in which to gain name and reputation, and having consulted with his elders in deliberation and intent, he set out with his squads (almost innumerable by then) and settled in Manta, and in Charapoto, and in Piquaza, because in less space could not house or sustain so many nations as he brought behind him. It was in this place where king Topa Ynga saw the sea for the first time, to which, as he discovered it from a height, he made a very deep adoration, and called it Mamacocha, which means mother of the lagoons, and he gathered a large quantity of the boats that the natives used (which are certain remarkably light sticks) and tying them tightly together, and making a certain roof of woven reeds on top, it is a very safe and comfortable boat, which we have called rafts. Having collected the quantity of these that seemed to him sufficient for the people he intended to take with him, taking from the natives of those coasts the most experienced pilots he could find, he went into the sea with the same spirit and courage as if he would have experienced its fortunes and dangers [of the sea] from his birth. On this trip he moved farther from the mainland than one can easily believe, for those who tell the story of this brave Ynga affirm that on this journey he was in the sea for a year, and they also say that he discovered certain islands, which they called Hagua Chumbi and Nina Chumbi. What islands are these in the South Sea (on whose coast the Ynga embarked) I will not dare to affirm with certainty, nor what land is the one that can be found in this navigation. The reports that the ancients give us about this trip are that he brought black Indian prisoners from there, and a lot of gold and silver, and a brass chair, and hides from animals like horses...

The second author wrote in his chapter XXV:

On this occasion some ancient Indians say that he embarked on the sea in some rafts on the island of Puna and went to Manta, and from there he sailed for a year by sea and reached the islands called Hahua Chumpi and Nina Chumpi and conquered them, and from there he brought, to show off his triumph, a people like negroes, and a great quantity of gold and a brass chair. He brought horse skins and heads and bones, all to show it here, as it was an ancient custom among these Ingas to bring all the showy things that could cause admiration and fear to Cuzco, so that they could see them and magnify their exploits, and to keep the memory of the things that happened in the other remote provinces. It is understood that all these trophies were burned later by Quesques and Chalco Chuma, captains of Atahualpa, when they took Cuzco, making Huascar Inga prisoner. There they burned the body of this Tupa Ynga Yupanqui, because no memory of all these things was found when the Spaniards came.

Others say that this conquest of these lands and islands was made by Tupa Ynga Yupanqui during the lifetime of his father Ynga Yupanqui, when he went to Quito and conquered it with his brothers. Both opinions may be kept, because it doesn't matter if it was at one time or another.

Of these islands that Tupa Ynga Yupanqui conquered in the sea, today there is no certain news, more than the confused one of those who say that there are islands with somewhat mulatto people, and other ancient Indians, who refer that in past times of the Ingas, some people came from certain islands to the coast of this kingdom, in very large canoes or rafts, to exchange gold and pearls and large snails, very rich and dressed in cotton. This has stopped altogether...

Some researchers, aware of the many Polynesian legends about long-eared sailors arriving from the east, assume that the voyage was real and that it reached Rapa Nui or other islands in Oceania.

Only a few authors keep maintaining the hypothesis that the islands visited by Tupaq Yupanki, the regent of the Tawantinsuyu or "Inca Empire", could have been the Galapagos.

[The photograph that illustrates this text corresponds to a landscape on Isabela Island, and was taken by Edgardo Civallero].