The pupils of Mount Pleasant School, like most other schoolchildren in Southampton, were evacuated to Dorset right at the beginning of the Second World War. They assembled at the school on September 1 and set off in crocodiles for the station and an uncertain future in the country.

When the massed fleets of bombers and gas attacks from the air failed to materialise during the autumn and winter, homesick youngsters began to drift home and in the New Year, the school reopened.

Some of the pupils had already been introduced to the vaulted cellars during pre-evacuation air-raid drills.

Once the air raids began for real, those who lived close to the school became very familiar with the parts of the underground area which were fitted with bunkbeds.

There was enough room for the whole school to be accommodated in the event of daytime raids and enough space left over for other purposes.

The extensive basement area had come about because, in the days when the school was built, the River Itchen was much closer and there was always a danger of water levels rising.

There was even a sign on a house just past the level crossing which advertised ‘Boats for Hire’.

By 1939 sufficient land had been reclaimed and drained so that the cellars were no longer at risk of flooding.

Mount Pleasant therefore became much more than just an air raid shelter.

While the school went about its business of educating by day and the public sought protection from bombs by night, the building and site was a fully operational headquarters for civilian ambulances - one ambulance driver, Mollie Tinsley, was awarded a George Medal for her work - and an A.R.P. (Air Raid Precautions) Control Centre with associated nurses, doctors, canteen staff, telephonists etc.

Ambulances were lined up in the playground, next to the bike shed, and beside them was an ex-corporation single decker bus converted into a simple mobile operating theatre.

Parts of the underground space were used for a mortuary area and a decontamination unit.

Many years after the end of the war and after much of this activity had been forgotten, John Hayward took over the headship at what was then Mount Pleasant Middle School.

He was intrigued by a concrete canopy mounted on a steel framework in the playground.

He discovered that this had been erected to protect anyone using the steps to the cellar from flying shrapnel and, of course, that led to him exploring the shelter which had been used as a handy storage facility by a local amateur dramatic society.

He was struck by the amount of history encapsulated in these spaces - signs saying how many children could be allotted to different areas, the off-set entrances to counteract blast and most compelling of all, drawings done by children on the paintwork next to their bunkbeds.

John was determined to share this peek into the past with others and he began by organising a day, in 1995, that would enable current pupils to take ex-pupils on a tour of the shelters and then to give the older generation an opportunity to share their wartime memories with the youngsters.

This day proved to be a great success, with both the children and their visitors feeling that they had learned a lot.

John, now retired, still has a folder of letters from ex-pupils who attended the event; some passing on more memories – a girl running down Derby Road, pursued by machine gun fire from a German plane, until she reached the sanctuary of a shop, the boys competing to see who could find the shiniest piece of shrapnel - and other letters complimenting him on the behaviour and manners of the young people they had met.

Dreams of opening up the shelter for display on a more regular basis did not materialise. Asbestos was discovered and the basement was closed.

Perhaps one day it will be reopened and made safe.

Ally Hayes is a tour guide with SeeSouthampton.co.uk .