The principal gorges are (see reference for note about these measurements): 
" First Gorge: the one the river falls into now
" Second Gorge: (spanned by the Victoria Falls Bridge), 250 m south of falls, 2.15 km long (270 yd south, 2350 yd long)
" Third Gorge: 600 m south, 1.95 km long (650 yd south, 2100 yd long)
" Fourth Gorge: 1.15 km south, 2.25 km long (1256 yd south, 2460 yd long)
" Fifth Gorge: 2.55 km south, 3.2 km long (1.5 mi south, 2 mi long)
" Songwe Gorge:5.3 km south, 3.3 km long, (3.3 mi south, 2 mi long) named after the small Songwe River coming from the north-east, and the deepest at 140 m (460 ft), at the end of the dry season.
" Batoka Gorge: below the Songwe, the gorge is called the Batoka Gorge (which is also used as an umbrella name for all the gorges). It is about 120 km (75 mi) long (the straight line distance to its end is about 80 km (50 mi) east of the falls) and takes the river through the basalt plateau to the valley in which Lake Kariba now lies.
The walls of the gorges are close to vertical and generally about 120 m (400 ft) high, but the level of the river in them varies by up to 20 metres (65 ft) between wet and dry seasons.
How the Victoria Falls formed
"Leaping Waters", the westernmost cataract of Victoria Falls and the start of a line of weakness where the next falls will form.
The recent geological history of Victoria Falls can be seen in the form of the gorges below the falls. The basalt plateau over which the Upper Zambezi flows has many large cracks filled with weaker sandstone. In the area of the current falls the largest cracks run roughly east to west (some run nearly north-east to south-west), with smaller north-south cracks connecting them.
Over at least 100,000 years, the falls have been receding upstream through the Batoka Gorges, eroding the sandstone-filled cracks to form the gorges. The river's course in the current vicinity of the falls is north to south, so it opens up the large east-west cracks across its full width, then it cuts back through a short north-south crack to the next east-west one. The river has fallen in different eras into different chasms which now form a series of sharply zig-zagging gorges downstream from the falls.
Ignoring some dry sections, the Second to Fifth and the Songwe Gorges each represents a past site of the falls at a time when they fell into one long straight chasm as they do now. Their sizes indicate that we are not living in the age of the widest ever Mosi-oa-Tunya.
The falls has already started cutting back the next major gorge, at the dip in one side of the 'Leaping Waters' section of the falls. This is not actually a north-south crack, but a large east-north-east line of weakness across the river, and that is where the next full width falls will eventually form.
Further geological history of the course of the Zambezi River is in the article of that name.
Archaeological sites around the falls have yielded Homo habilis stone artefacts 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 (bushmen) displaced these Stone Age people and in turn were displaced by Bantu tribes such as the southern Tonga people known as the Batoka/Tokaleya, who called the falls Shungu na mutitima. The Matabele, later arrivals, named them aManza Thunqayo, and the Makololo (whose language is used by the Lozi people) called them Mosi-oa-Tunya. All these names mean essentially the same thing, 'the smoke that thunders'.
The first European to see the falls was David Livingstone on 17 November 1855, during his 1852-1856 journey from the upper Zambezi to the mouth of the river. The falls were well known to the Batswana, Matabele and Balozi, but Europeans were sceptical of their reports, perhaps thinking that the lack of mountains and valleys on the plateau made a falls unlikely. The Arabs may have known of them under a name equivalent to 'the end of the world'.
Livingstone had been told about the falls before he reached them from upriver and was paddled across to a small island that now bears the name Livingstone Island. Livingstone had previously been impressed by the Ngonye Falls further upstream, but found the new falls much more impressive, and named them after Queen Victoria. He wrote of the falls "No one can imagine the beauty of the view from anything witnessed in England. It had never been seen before by European eyes; but scenes so lovely must have been gazed upon by angels in their flight".
In 1860, Livingstone returned to the area and made a detailed study of the falls with John Kirk. Other early European visitors included Portuguese explorer Serpa Pinto, Czech explorer Emil Holub, who made the first detailed plan of the falls and its surroundings in 1875 (published in 1880), and British artist Thomas Baines, who executed some of the earliest paintings of the falls. Until the area was opened up by the building of the railway in 1905, though, the falls were seldom visited by other Europeans.