The group was fighting against the construction of a massive new motorway through the area, that would have ruined the context of Andrea Palladio's famous villas.
Conservationists also warned, when the plans first emerged two years ago, that the road would bring with it vast numbers of retail sheds.
But Romano Prodi's new left-leaning government has suspended the previous Berlusconi administration's plans for the motorway in the World Heritage Site.
And the Italian government is now set to investigate the deal which confirmed the construction.
The proposed motorway, the Valdastico Sud, had been approved by the previous government despite objections from the Ministry of Culture and the Sovrintendenze [official monuments services for archaeology and heritage].
Marcus Binney, chairman of Save Europe's Heritage, said: 'For years Italy has set an inspiring example to the world in the protection of its great buildings.
'The Sovrintendenze for monuments and archaeology are among the most professional and respected bodies of their kind in Europe.
'Yet the [previous] Italian government brushed aside their advice and legitimate concerns,' Binney added.