This is a lovely estate, one of the last remaining properties in the Mérignac gravel area, lying next door to Haut Brion and Pape-Clément. The name Caillou refers to pebbles, reflecting the fact that this was once riverbed, when the river Garonne overflowed millions of years ago. The characteristic elegance and finesse of this wine is attributed to its free-draining, gravelly soil and subsoil. Sadly the quantities of white produced are tiny as the wine is lovely. The blend in 2016 is 90% Sauvignon Blanc, 10% Sémillon with 8 months on the lees in wood.