Which historical/legendary/mythological accounts turned out to be true?

Question

Reading Herodotus' Histories, one is often baffled by passages like (3.102):

{102} [...] Indians [..., of the North] make expeditions for the gold. For in the parts where they live it is desert on account of the sand; and in this desert and sandy tract are produced ants, which are in size smaller than dogs but larger than foxes, for there are some of them kept at the residence of the king of Persia, which are caught here. These ants then make their dwelling under ground and carry up the sand just in the same manner as the ants found in the land of the Hellenes, which they themselves also very much resemble in form; and the sand which is brought up contains gold. [...] {105} When the Indians have come to the place with bags, they fill them with the sand and ride away back as quickly as they can [...]

This has long been considered just a legend, until Peissel [A] observed the existence of a species of marmot, the Himalayan marmot, in the gold rich Deosai Plateau in Northern Pakistan. The local people confirmed that they have been collecting the gold dust that the marmots bring to the surface when they are digging their underground burrows. Peissel also observes that the old Persian word for "marmot" was quite similar to that for "mountain ant", so Herodotus might have confused the two words.

A similar revision must have happened at some point, about the famous passage (4.42):

[...] as they sailed on a westerly course round the southern end of [Africa], they had the sun on their right - to northward of them.

But let's change book. In the logbook of the Carthaginian suffete Hanno, we read:

{18} In this gulf was an island, resembling the first, with a lagoon, within which was another island, full of savages. Most of them were women with hairy bodies, whom our interpreters called 'gorillas'. Although we chased them, we could not catch any males: they all escaped, being good climbers who defended themselves with stones. However, we caught three women, who refused to follow those who carried them off, biting and clawing them. So we killed and flayed them and brought their skins back to Carthage. For we did not sail any further, because our provisions were running short.

The account of these hairy women sounded unbelievable. But when the Europeans (re)discovered the giant apes in XIX century (this is 2500 year later), they called them "gorillas" after the account of Hanno.

The question: do you know any other historical/legendary/mythological account, that was believed implausible at first, but turned out to be plausible or even true? I know a few myself, but let's make a list! Please include a source/excerpt of the account, and described what changed its perception.

[A] Pessiel M., The Ants' Gold: The Discovery of the Greek El Dorado in the Himalayas, Collins, 1984

Answer 1

I think the Norse discovery of the Americas fit. Around year 1000, an expedition led by Norseman Leiv Eiriksson winter camped on Newfoundland.

From the Wikipedia article:

For some centuries after Christopher Columbus' voyages opened the Americas to large-scale colonization by Europeans, it was unclear whether these stories [of Leiv Eiriksson's discovery of Vinland, my remark] represented real voyages by the Norse to North America. The sagas were first taken seriously when in 1837 the Danish antiquarian Carl Christian Rafn pointed out the possibility for a Norse settlement in or voyages to North America. North America, by the name Winland, was first mentioned in written sources in a work by Adam of Bremen from approximately 1075. It was not until the 13th and 14th centuries that the most important works about North America and the early Norse activities there, namely the Sagas of Icelanders, were put into writing.

The question was definitively settled in the 1960s when a Norse settlement was excavated at L'Anse aux Meadows in Newfoundland by archaeologist Anne Stine Ingstad and her husband, outdoorsman and author Helge Ingstad.

Icelanders (and Norwegians from the 1800s onwards) might have been "certain" all along that the stories of discovery were true, but I do not think it was accepted by everyone in the rest of Europe / North America until the archeological discoveries. There are several other, unconfirmed stories of trans-Atlantic contact, so it would have been feasible to group the Norsemen with these as long as no "hard evidence" was found.

Answer 2

I'll start with the archetypical story of the type: Troy.

Up till 19th century, people believed that Homer's and Virgil's troy was a legend, not a real city (unlike Greeks and Romans).

In 1865/1868, Calvert and especially Heinrich Schliemann have found what they believed to be real Troy (though later archaeology, fully detailed on Wikipedia, showed that Schliemann actually found earlier Troy II, whereas Homeric Troy is usually though not conclusively placed as Troy VIIa).

Answer 3

The Archimedes Heat Ray seems to be a good example.