Beaune is the wine capital of France's Burgundy region. Above ground, the old fortified city is already beautiful. But the real treasure is hidden below the surface, down in the cellars. They contain two million bottles of wine, in a total of five kilometres of galleries, all linked together. One of the oldest cellars in Beaune has been occupied for four generations by the Maison Drouhin. It contains traces of the city's ancient past. Meanwhile, the cellars of Maison Champy were once frequented by Louis Pasteur and Gustave Eiffel. The much more modern Jadot winery has an unexpected skylight. FRANCE 24 takes you to discover these hidden treasures.