Château Ducru-Beaucaillou owes its name to its "beautiful pebbles" ("beaux Cailloux", in French) that geologists refer to less romantically as Gunzian gravel. These quartz pebbles were deposited by the ancient Garonne at the beginning of the early Quaternary period, some two million years ago. It suffices to take a walk through the vineyards to make rich lithological finds. Lydian jasper from the Pyrenees, flint, quartz, agatoids... These Gunzian gravels make for soils that are poor in plant nutrients. But it is their very agrological paucity that guarantees the qualitative excellence of the wines. A choice of nature.