Protest organisers say around 8,000 people gathered on the field where the proposed Notre-Dame-des-Landes airport is to be built.
The protest, resembling an outdoor music festival, saw protesters flying kites, calling for the skies above to be kept free of aircraft.
It is a “symbolic action…to say the sky should be kept free, like the ground at Notre-Dame des Landes,” said Anne-Marie Chabod, the co-president of Acipa, an organisation which has organised protests on the site for 13 years.
An airport at the Notre-Dame-des-Landes site was first proposed in the 1960s. The 580 million euro project was approved in 2008 and intended to replace Nantes Atlantique airport, which its operators say cannot be expanded to increase its current capacity of three million passengers a year.
However, opponents to the new airport say the existing airport can increase its capacity.
Thierry Brulavoine, a municipal councillor for the Saint-Nazaire department, said the new airport is not needed.
“During this time of economic crisis, public money should be used on things other than useless projects,” he said.
The controversial airport plan is dear to French Prime Minister Jean-Marc Ayrault, who used to be mayor of Nantes. The project has split the government.
Construction is expected to start in 2017 or 2018.