It was hardly noticeable at first, though millions are being spent. But as more and more of the historic buildings in the capital are restored, Valletta is slowly starting to shine, as the grime of time is removed from the stonework.
Just one quick look at upper Merchants Street and Melita Street will show the results of the work done so far: the area virtually glows, after the external restoration works on St Catherine of Italy Church, on the Foreign Ministry, and in Melita Street, corner with St Paul Street.
The contrast is stark as one compares the now shining white stonework of the foreign ministry, the former Palazzo Parisio, with the adjoining traffic-polluted walls of the Auberge de Castille, which is badly in need of restoration.
The capital's founder, the eponymous French Grand Master Jean Parisot de La Valette could have little foreseen in 1565 the grime that would coat most of the buildings centuries later - in his time there were no power stations, and no cars, and horses polluted only the road, not the buildings.
The horses are still at it, of course - doing nature's thing - and recalcitrant horse-drawn cab drivers still do not seem to be seeing reason. But apart from road pollution by the horses, traffic and industrial smog today clings hard and fast to the buildings, turning the attractive Maltese stone into ugly, blackened façades.
Various bodies are involved in the work going on. For instance the external restoration of the Foreign Ministry was done by the restoration unit of the Ministry of Infrastructure, and financed by the Foreign Ministry.
But much of the restoration work is being done by the Infrastructure Ministry's Valletta Rehabilitation Project, which has now been active for 15 years.
Its executive coordinator, Ray Bondin, said the VRP has carried out works in all the major buildings in Valletta.
During the first years attention was given mainly to the jewel that is St John's Co-Cathedral and to the President's Palace, but restoration work has also been done on many other buildings, mainly auberges and churches.
Extensive works were done, for instance, on the Jesuits Church, St James Church, Our Lady of Pilar Church, the Auberge de Provence, the Auberge d'Aragon and various others. Most of these works concentrated on the "building fabric".
Environment improvement plans concentrated on the upgrading of pedestrian areas: Republic and Zachary Street, Queen's Square and St John Square.
Mr Bondin said that in recent years the VRP has also carried out major restoration work on bronze statues, such as Vilhena's at Floriana, and Algardi's at St John's, on the Paladini and Perez d'Aleccio frescoes at the Palace, and on various paintings, including in the Jesuits church.
And today the VRP is concentrating on upgrading the three main gardens - the Upper and Lower Barrakka and Hastings.
The VRP is also continuing with various restoration works at the Palace, St John's and now, Our Lady of Victory church, opposite St Catherine of Italy church.
"At any one stage we have around 12 major projects going on in Valletta alone," Mr Bondin said.
Asked about the VRP's future plans, Mr Bondin said the VRP wished to finalise projects that were started, without undertaking new ones.
"For instance we are concentrating on finalising the Paladini and Perez d'Aleccio frescoes restorations, as well as the Jesuits Church and Our Lady of Victory.
"We are also planning a major upgrading of part of Merchants Street and St John Square."
It has been costing millions over the years, paid for by the government, though EU money was made available for St John's in 1989. There have also been some small sponsorships.
There are so many historic buildings in the capital, all in need of attention, that by the time the work is completed, if it ever is, those which were restored first will again be in need of it.
For, as Mr Bondin said, the VRP had very limited funding for maintenance.
"Protection against pigeons is one of the obvious problems and normally after a façade restoration is finished we do provide for protection against pigeons. But this does not last more than four or five years," he said.