Recognised by the French government-run Regional and Heritage Sites Commission of the Midi-Pyrénées (CRPS), the 0.2ha vineyard, in the village of Sarragachies in Gers, was listed due to its "exceptional character and cultivation methods over the past century".

The vineyard benefits from a sandy sub-soil which has enabled it to resist phylloxera, the insect responsible for decimating entire wine regions around Europe in the late 19th century.

For generations its owners have protected the vineyard using traditional viticultural methods, such as double vine-stock planting and it contains around 20 individual different grape varieties, including seven unidentified to date.

This recognition, a first in France, is the culmination of a long-standing commitment by Producteurs Plaimont to preserve the heritage of historical vineyards and guarantee the future of appellations from the Pyrenean foothills.

Olivier Bourdet-Pees, managing director for Producteurs Plaimont, said: "We are absolutely delighted to gain such a prestigious recognition. It is in this region that a great number of grape varieties used in the south west and on the Atlantic coast were born, such as Cabernet Sauvignon.

"Some varieties in this ancient vineyard have been completely forgotten and we are still carrying out tests to determine what they are."

Plaimont Producteurs is actively involved in ampelography, the study of vines and grapes, and set up the Conservatory of Saint Mont in 2002, where it claims to have saved many grapes from extinction, including Pinenc, Petit Courbu and Arrufiac, which are now used in the majority of the company's wines.