The Games in the Swiss city - the Olympic capital - is due to begin with the Opening Ceremony on January 10 in 2020.

More than 60 people met today in a restaurant in the Flon district of Lausanne to mark the milestone.

Among those involved were representatives from the City of Lausanne, the Canton of Vaud, the Swiss Olympic Committee and National Sports Federations. 

Stakeholders from competition venues were also present, including those from France.

This was after the Tuffes Nordic Stadium, located across the French border, was chosen as the venue for ski jumping, biathlon and Nordic combined.

The International Olympic Committee (IOC), whose headquarters are in Lausanne, were also represented.

Patrick Baumann, the SportAccord President who also heads the Lausanne 2020 Organising Committee, said: "This symbolic date is an opportunity for us to pause for a moment and appreciate the quantity and the quality of the work carried out to date. 

"These groundwork activities are not the most visible to the general public, but they are vital for the future success of the event. 

"I am particularly pleased with the long-term legacies that we have already established, such as the desire of Swiss Ski to make Diablerets a training centre for our future ski stars. 

"Our wish to extend the event to all of Switzerland by involving St Moritz for snow sports is also very good news and a great motivation for our sporting youth."

Lausanne comfortably saw off the challenge of Brasov in Romania to win the rights to the 2020 Games at the IOC Session in Kuala Lumpur in 2015, triumphing by 71 votes to 10.

Ian Logan, chief executive of Lausanne 2020, said: "For me, this first year of work has given me great satisfaction. 

"We have succeeded in bringing together a large number of partners who all share our desire to go beyond the organisation of a simple international sports competition by exploring all possible educational and cultural aspects. 

"I would particularly like to thank the schools of the Canton of Vaud which, through the Department of Education, Youth and Culture, have committed themselves in a way that has gone above and beyond our expectations. 

"Their support is a sign of great confidence which reinforces our motivation to put together something strong and striking, for the young people of Vaud and Switzerland, in 2020 and beyond."

Lausanne 2020 are currently finalising their "Games Foundation Plan" which is due to be submitted to the IOC in March.