Blackgang Chine you may know to be long-running Isle of Wight coastal amusement park. It was established by Victorian entrepeneur Alexander Dabell, who saw a triple opportunity in the "steep gaunt ravine", the popularity of a nearby chalybeate spring and the skeleton of a beached whale to exhibit, and set up what was probably the first British theme park. Blackgang Chine was first documented in the 1700s. While writing another article a while back, I asked the current owner, Simon Dabell, about its history; he told me that it was "a visited geographical location for at least 100 years before his great-great-grandfather opened the gorge as an attraction in 1842/3" (there are early engravings dated around the 1760s). "However the island was rarely visited by non residents before the 1750s so the mists of time cover any earlier knowledge of the site".
The Chine features in many paintings and prints of the 19th century. This 1816 Peter de Wint print, Black Gang Chine and these images from the 1834/1845 Barber's Picturesque Illustrations of the Isle of Wight, show the waterfall at its foot; and there are various offshore views: the 1837 Brannon print at the NMM showing the wreck of the Clarendon at its foot, and this scene by Charles Cousen, published in The History of Hampshire, 1869. Queen Victoria and Prince Albert visited in 1843, many Victorian travel guides and accounts mentioned it; it inspired poetry;
Far to southward of Thule's island, by the craggy shores of Wight
Wild and drear, and very lonely, falling on the stranger' sight,
Frowns in all its primal grandeur, like an earth-discovered mine,
What, from ages immemorial, ancient men have called the Chine.
Black-Gang Chine, J. Albert Way, The Ladies' Companion, Bradbury and Evans, February 1855 - Google Books
and it even turned up in novels, such as Captain Marryat's 1837 Snarleyyow - Or, The Dog Fiend (see the description in Chapter XVI) and Charlotte Mary Yonge's 1889 A Reputed Changeling. Both involve smugglers, and the latter literally features a Black Gang operating there, fostering an apocryphal smuggling etymology (in fact, although undoubtedly smuggling went on, "Blackgang" just means "black way").
However, chines, on a geological time scale, are ephemeral features. They're formed by a nicety of circumstance - seaside stream, soft-rock geology, and ongoing cliff recession - which stimulates rapid erosion. Blackgang has the added factor of being at the end of the Isle of Wight Undercliff, an active landslip zone, which made it ephemeral even on a historical time scale, The landscape had long been known to be fluid. Marryat's Snarleyyow describes the area in 1699, saying that "since that period much of the cliff has fallen down, and the aspect is much changed", and Black's Guide said in 1870: "A fearful fall occurred in February 1799, when a farm near Niton, called Pitlands, and about 100 acres of land, were rent to pieces at one sudden catastrophe. At east end, in 1810, 30 acres were uptorn in a similar manner, and 50 acres in 1818".
The 1869 Charles Cousen print is probable the nearest thing we'll get to a mid-19th century photorealistic image where you can actually identify the geology: the lower brown section of Lower Greensand, with a white topping of what appears to be Upper Greensand Chert Beds or even Chalk, which made this an unusually complete section mentioned in geological texts such as Conybeare & Phillips' 1822 Outlines of the Geology of England and Wales, with an Introductory Compendium of the General Principles of that Science (see Google Books). However, erosive change began to be very evident by the late 1800s, when a lower-level road was carried away. The Chine was still an accessible and impressive, if rather softer-looking, ravine as shown in this 1890 photochrome and early 1900s postcards at Bartie's website. But the process went on over the 20th century, as shown in these postcards from shalfleet.net. At some point the capping was lost (the Chert Beds are still visible in Gore Cliff behind the amusement park) and the ravine became progressively blunted until now there's just a broad concave area of landslip (see this aerial image at Phil Brace's Isle of Wight Gallery).
The Blackgang Chine amusement park is still hanging in there, though forced to constantly adapt to the changing cliffscape - see Isle of Wight Nostalgia - Blackgang Chine Theme Park - The battle against erosion. I was pleasantly surprised to see, even though the park's theme has drifted from eccentrically genteel to child-orientated, the whale skeleton and Wishing Chair (that I remember as a child, my family being from the Isle of Wight) are still there. Perhaps that explains my abiding interest in this place: this piece of landscape progressively fraying away is a very literal metaphor for the departure of the past into memory, rather like Stephen King's 'Langoliers' that devour the fabric of the past or "the mechanism" in William Gibson's Agrippa (of which more later).
Other chines, however, still exist, and are strangely varied for such small geographical features. My favourites on the Island are Shanklin Chine and Whale Chine, both of which are considerably more stable features as they're outside the Undercliff landslip. The first - see the official site - is a cosy wooded place with waterfalls that has charmed visitors for at least two centuries, and hasn't radically changed over that time, as Brannon prints and later postcards show. The second, in contrast, is stark and weird, almost Martian in appearance - see this and other images at Geograph.
See also: The Silence of Dean Maitland.
Addendum: see the 2011 update, IOW (3): Return to Blackgang.