The honour of officially opening the caves on May 29, 1985 went to the then Director of Tourism with Fermanagh Council, John Crichton, who said the project reflected the great courage of the council in going ahead with the idea and seeing it through to completion.
And the Chairman of the Council, Mr. Caldwell McClaughry speaking at the launch said: "The caves are not only of value in tourist terms, but I'm sure will also be an important and meaningful resource in terms of education".
Twenty-five years on and they continue to be just that. Visitors come from all over the world to enjoy outings to this "fascinating underground world".
The journey through tunnels, paths and lakes - involving a short boat journey - takes 75 minutes with a guide explaining the various scenes, including the famous stalactites.
The years have certainly rolled on from the discovery of the Marble Arch complex in 1895 by the famous caves explorer, French man Edouard Alfred Martel - the first person to enter the caves and do a systematic exploration.
In 1897 - in his book published on caves in Ireland and England - he devoted almost a chapter to Marble Arch Caves and thought they would make a fine tourist cave.
Hence, he is acknowledged for coming up with the concept - which 90 years later became a reality - thanks to the project being pursued by John Crichton and also by Gerry Burns, in his role as Clerk and Chief Executive.
Three current members of the team at the Marble Arch Caves Global Geopark have been on the staff from the caves' public opening - Richard Watson, Geopark Manager, started in January 1985; Arthur Roche, Supervisor, actually started in 1982 when work started on developing the caves; and Geraldine McGovern, Administrative Officer, officially started on April 8, 25 years ago.
Richard, a son of the late George and Chrissie Watson, who had done some caving with Major Wheeler and Colonel Halpin during his schooldays at Portora and had studied the geology of Marble Arch for an A'level - recalls being present on the day that the caves opened to the public.
A short time earlier, a BBC crew spent a week filming a programme on the caves, which at that time featured Neil Hannon, as a member of St. Macartin's Cathedral choir.
Over the years, the caves have attracted many famous names and now attract visitors from over 100 different countries.
Visitor numbers remain steady, although Richard mentions that tourism is affected by outside factors, for example the current volcanic ash situation.
And even when the caves opened for the new season at Easter this year, they were affected by the weather - the county's fall of snow!
However, they are hoping for a good summer at the famous attraction, which appeals to not only visitors from afar, but local people who bring friends and relations, and also many school groups.
Richard, Arthur and Geraldine, who greatly enjoy their work and the many people they meet, were speaking on Tuesday as the caves hosted schoolchildren from Drogheda; their educational visit included the cave tour and also a visit to Cuilcagh mountain park looking at the limestone.
Members of Herefordshire Geological Association were due to visit yesterday, Wednesday, and in early June, they will welcome a visiting group from Hong Kong. "They are hoping to develop a Geopark and are looking at the geology of Northern Ireland," explained Richard, who mentions that the province is one of the most diverse geological regions for its size.
In reference to the Marble Arch project, Richard Watson acknowledges people's faith, confidence and vision to look forward.
"Collectively we and other people have been given the responsibility of getting on with it and developing it," said Richard, who believes they have done pretty well.
Over the years, Richard admits there have been ups and downs, for instance losing colleagues, such as Conor Burns, who was totally dedicated to his work at the caves.
However, on the up side, he finds it satisfying to see people coming from all over the world and the favourable comments that are made. As well as receiving repeat visitors, seeing people enjoying themselves is another gratifying aspect.
And as the years progress, the Marble Arch Caves Global Geopark has gone on to greater things.
But then, putting it into perspective in relation to human time and cave time, the scene inside the caves remains 'virtually unchanged'.
"The fastest growing stalactite has grown about one tenth of a millimetre in 25 years," explains Richard, who says if Martel came back after 130 years, nothing would have changed.