Not to be confused with the Netherglades Swamps in Quirm, this country/region is located on the turnwise coast of the Central Continent with its neighbours being Genua to the turnwise and Brindisi to the widdershins. It is bordered to the hubwards by a region un-named on the map but which may be a part of either Mouldavia or Muntab. One of a chain of four islands is marked as belonging to the Neverlands, whilst the remaining three are marked as part of Kythia.
There is a reference to the country having once been populated by a race of giants who dug deep canals so as to drain the land for farming and habitation, and who built high thick dykes to reclaim more land from the sea. Windmills and tulips are not mentioned but can be presumed to not be far behind. The Neverlands has a crescent-shaped coast and a huge bay, known in the ancient language as De Wendersee. It is implied that the island chain stretching from the Turnwise peninsula of Brindisi to the widdershins peninsula of Kythia (marking the extremes of the bay) is all that remains of what was formerly a huge dyke enclosing what once was reclaimed land; the sea broke through in several places and reclaimed the land, precipitating the end of the original Neverlands civilization.
These days it is the home of a hardy seafaring people who may have found and colonised other lands, but are renowned for being fierce rapacious pirates. Indeed, pirate language and law prevails in the country today, and the Neverlands' insular posession of Barrie Island now hosts a Free Port, amusement centres, casinos, and a Pirate theme park depending on the tourist trade and ferry boats from the nearest thing to a capital city, Hooke Point. The residents have found this to be a far simpler, easier, more risk-free and above all lucrative method of piracy than merely running down other peoples' ships and capturing them and their cargoes.
The references to a Discworld version of Holland with all the knobs turned up to eleven - or at least, some of the knobs marked "Holland" - are suspicious. And in the seventeenth and eighteenth centuries, the Dutch were indeed the world's foremost maritime power, even raiding London with impunity in the late 1600's. The Dutch mercantile fleet (like the English of the time) had the world's best fighting ships and only common courtesy, plus an awareness they had the best fighting navy, prevented everyone else from calling Dutch mercantile venturers "pirates".
Barry Island is a holiday resort in South Wales made famous by TV romcom Gavin and Stacey and is indeed the epitome of shabby, rundown, British coastal resorts where you just know everything is set up to rob you blind.
And of course J.M. Barrie is the author of Peter Pan, a fantasy adventure featuring the Lost boys of er - Neverland in their incessant battle with Captain Hook's pirates... and do we need to mention Michael Jackson....
The coastline of the Neverlands even evokes a horizontally flipped Holland, with the Wendersee having overtones of the Zuiderzee/IJsselmeer and the island chain being where you'd expect to see the West Frisian Islands. Hell, on a map of the Netherlands, the water inland of the Frisians is called De Woddenzee. the Other Wiki also notes that in the early mediaeval period, the Netherlands was under extreme danger of being overtaken by the sea unless drastic measures were taken: the massive civil engineering works that transformed the country began here, with the construction of the polder system of man-made sand-dunes, dykes and drainage systems. Which took seven hundred years to create the Holland we know today. Is this what Terry was thinking about when he created the legend of long-gone giants building the dykes and barriers? (As people will when they look around and see clearly "made" old things. If the things they see are beyond their own level of organisation and technology, people always consider it would have been impossible for mere humans to conceive or build such marvels. After all, the Saxons thought the Roman roads and remains they found in England, like Hadrian's Wall, were the work of long-gone giants... and don't get started on pyramids and aliens!)