It's the time of year when schools fall silent for a few summer weeks, when the children's feet stop and no bells ring. At Leeds Girls' High School this month, though, it's different. There's the sound of 132 years of history being cleared out and, down the corridor from the hall, there's the creaking of a unique oak library being expertly dismantled.

Only when all that is done will the silence of the school begin, and then it will never end. When the girls start the autumn term, they will be a few miles away, in a modern mixed school with a 21st century name: The Grammar School at Leeds. They will be in a green field site beyond Alwoodley; their head will be a man; they will share the place with the boys who have already been there for several years. Of course, it's not the first change of name, home or status that the school has known since its foundation in 1876, but it's certainly the greatest and one that brings a lump to the throat of those of us who loved the old place in Headingley.

The new school, with facilities undreamt of before, is exciting; so is the idea of teaching the sexes separately between 11 and 16 but together before and after that. And, of course, we ex-pupils of LGHS wish GSAL all the luck in the world. But we'd also like a little space to think of and thank the past.

Last time the school moved, in 1906 from St James's Lodge in Woodhouse Lane to the home it is leaving now, the pupils went all over the old place saying goodbye even to "the attics where we used to change for gymnastics, shaking the black beetles out of our tunics before we put them on," as one girl recalled in the school magazine. And this summer, one glorious Saturday and a rather rainier Sunday in May, more than 1,400 of us did the same thing, although without the beetles, when our old school declared open house for the weekend and let us ramble at will down corridors and down memory lanes.

We were saying goodbye to something special. The school began in pioneering times for girls' secondary education: what later became the Girls' Public Day School Trust was already opening its schools, with Princess Louise, daughter of Queen Victoria, as its patron. North London Collegiate School and Cheltenham Ladies' College had shown others the way in the 1850s.

In true Yorkshire style, the movers and shakers of 19th century Leeds went it alone and founded the school, through the Yorkshire Ladies' Council of Education and the Leeds Ladies' Educational Association, to be to the girls "what the Grammar School is to their brothers". The names of the founders and friends of the early school – Lupton, Tetley, Ford, Currer Briggs, Clark and many others – survived for more than a century in the prizes picked up by generations of girls at speech day in Leeds Town Hall and on the scholarship boards in the Headingley school.

It was a fight, both financially and philosophically. At the opening of the school, the right honourable Lord Hatherley remarked that there was "not the strength in the fibres of the brain as would enable the majority of girls to compete in the high branch of mathematics or other subjects of that kind requiring great mental power and attention". The first headmistress, Miss Catherine Kennedy, just 24 when she was appointed, trounced him shortly afterwards, announcing in her speech a curriculum that included French, Latin, German, maths and natural science.

Decades before women were admitted to degree status by the major universities, this clever woman set a pace for the school's future. During its various incarnations – independent, with as many bursaries and scholarships as possible, or direct grant, with 25 per cent free places – LGHS consistently hit the heights in the school tables.

In fact, the girls have generally had the academic edge over their brothers in the bigger and much older Leeds Grammar School. The boys and masters of GSAL should make no mistake: they are very lucky to have them.

When the school moved out to Headingley, the splendidly named second headmistress, Miss Helena Langhorne Powell, commented that the neighbourhood of Woodhouse Lane had deteriorated and become "less and less a residential quarter, and the street less fit for girls to walk in alone". It has to be said the same has happened in Headingley as Victorian family houses have become bedsit land. But it has been a special place, surely one of the first schools to have its own swimming pool (opened in 1927) and the first girls' day school to have a house system for various competitions. And in 1934 it became the proud owner of a remarkable library. Solid oak crafted by Mouseman Robert Thompson in his Kilburn workshop in North Yorkshire, it was the gift of an anonymous friend.

Going once again into the panelled room with its arched windows during our farewell weekend was a bittersweet return. There's no room I have loved so much and no doubt hundreds of Yorkshire women feel the same. That it could not be kept was one of the hardest things to take about the end of the school.

There we spent hours leaning on those tables, looking for the mice carved into each piece, avoiding games mistresses by hiding in the alcoves when we should have been playing hockey, reading bound volumes of Punch in the window-seat. It was full of years, of the smell of books, of wood and leather: simply a beautiful place to be. It has just gone under the hammer in lots at Tennants auctioneers in Leyburn. There was so much else to say goodbye to: rooms that meant different things to different generations. What had been our domestic science room was for older women the dining room, for younger ones another chemistry lab. The form-room daises on which our mistresses sat had gone, but the rooms were as small and cosy as ever.

It was a weekend that cropped up in our conversation and our dreams for days and even weeks. It is hard to believe that LGHS is over. What will happen to the organ to which we sang our hymns every day? When I was there, at least three members of staff could play it. What will happen to the old prefects' room where every year we inscribed our names on a parquet floor block? Of course, a school is more than its buildings. On that last visit my friend and I sat on the grassy bank in the sunny grounds, as we had done during so many lunch hours, and we realised how glad we were to have been in a school that let girls grow unhampered by what boys thought of them, that valued things of the mind more than shopping power and celebrity, that saw the way to real equality was through education. Selection and independence are both educational hot potatoes, but we benefited from a stillness and quiet confidence that few schools in the political flux can manage.

LGHS has always had many teachers who counted the decades, not the years, spent under its roof. These weren't just careers, but labours of love. And perhaps it's a good thing that our first headmistress, Miss Marion Sykes, who retired in 1970 and surely forever walks the school terrace with her West Highland terriers, died some years ago.

The future of today's pupils lies in plush new premises on a green field site, but those girls come from a past built among the elegant arcaded corridors and antiquated labs of LGHS at Headingley and before that created in a long-demolished house in Woodhouse Lane, where the inner ring road now runs.

They and we are the product of handful of determined Yorkshire women – and, vitally, men with money and influence – who believed in girls and in their education. Whatever corridors their ghosts roam, I hope they accept these few words of thanks.
Jill Parkin left LGHS in 1976.