When and where was the first waterfall discovered?

Answer 1

Your question makes a few assumptions that require explanation.

Waterfalls existed on planet earth before any human existed. 'Discovery' implies a documented -- i.e., written proof -- record showing the earliest date. Humans existed with oral traditions before they wrote; native peoples knew and understood the landscapes where they made their lives before 'discoverers' found them.

As a precise answer, however, one could offer this answer, from Wikipedia, about Victoria Falls in Africa, as an example:

"Archaeological sites around the falls have yielded Homo habilis stone artifacts from 3 million years ago, 50,000-year-old Middle Stone Age tools and Late Stone Age (10,000 and 2,000 years ago) weapons, adornments and digging tools.

"Iron-using Khoisan hunter-gatherers displaced these Stone Age people and in turn were displaced by Bantu tribes such as the southern Tonga people known as the Batoka/Tokalea, who called the falls Shungu na mutitima. The Matabele, later arrivals, named them aManz' aThunqayo, and the Batswana and Makololo (whose language is used by the Lozi people) call them Mosi-oa-Tunya.

"All these names mean essentially 'the smoke that thunders'.

"The first European to see the falls was David Livingstone on 17 November 1855, during his 1852--56 journey from the upper Zambezi to the mouth of the river."