From Discworld & Terry Pratchett Wiki
A grey granite edifice out on a lonely moorland which is, at first sight, indistinguishable from a maximum security prison. In fact, you could never subject prisoners to the sort of regime you get at Hugglestones, as this would infringe their human rights and they could lodge a successful complaint on the basis of the "cruel and unusual punishment" clause.
Hugglestones was built to lodge people who temporarily have no human rights at all - the sons of the rich, successful and influential, all those who because they rise to the top, society is best advised to publicly refer to as its "cream".
Designed to turn boys into men, the school tolerates a certain wastage in this process, generally of the fat, weedy and unfit. A certain route to survival is to run up and down the sports field shouting enthusiastically, but unaccountably just too far away from where the ball is/flying sticks are. This engenders a reputation for being "sporty" and other character flaws and eccentricities, such as being able to read without moving your lips or using your index finger, may then be excused.
The school staff believed that in sufficient quantities being keen could take the place of lesser attributes like intelligence, foresight and training.
Alumni include William de Worde, a man with a talent for language, who made sure by being perceived to be good at sports that the other half of his day was put to good use in the library.
Mrs Bradshaw's Handbook relates how Hugglestones' Academy now has its very own dedicated railway stop, on the Zemphis line. (As in "annotations" below, this is slightly and suspiciously reminiscent of another school in fiction with its own railway service. hmm.) This is necessary for transport of temporarily immobilised or disabled students, or for freighting the occasional coffin draped in the school colours. Georgina Bradshaw relates that the experience is a not unfamiliar one from her own schooldays. But also manages to hint that the wastage rate here is heavier than at the Assassins' Guild School.
Another public schoolboy who worked out that the best way to get a reputation for sporting excellence was to run up and down the sports field shouting enthusiastically, but unaccountably just too far away from where the ball is/flying sticks are, was Harry Flashman, the school bully in Tom Brown's Schooldays.
It has been suggested that the name "Hugglestones" has echoes of "Hogwarts School of Witchcraft and Wizardry" in a certain series of books by a certain J.K. Rowling, but not everyone agrees. And Hugglestones, of course, is not a school for Wizards. however, JK does coin a certain word to describe those, in her part of the Multiverse, who are not magically gifted. That word is of course Muggles. Is this another echo? Or maybe the initial echo the original writer was groping for but could not quite recall?
Another possible location to which it refers is 'Ampleforth College', a private school in the north of Yorkshire (literally on a rain soaked moor), the Junior school of which (Gilling Castle) is believed to have provided some inspiration for Hogwarts (which may explain why it contains echoes thereof). However, it is more likely that it is simply intended to reflect British public schools in general. On Roundworld is found another similar educational establishment for the unlucky sons of privilege. Gordonstoun in Scotland is grey, grim and Spartan to this day. The U.K.'s current reigning monarch and her consort - especially her consort (a man whose public pronouncements suggest he has much in common with Lord de Worde the elder) - thought it an ideal toughening ground for the luckless Prince Charles, which may explain much about the man he has grown up to be.