Château du Tertre is an estate located in Margaux in the "Left-Bank" Médoc region of northern Bordeaux, France. The château was classified as a fifth growth in the 1855 Classification of the Médoc and Graves. It is one of the oldest properties in Bordeaux, dating back more than 1000 years. The 52 hectares (128 acres) of vineyards have changed little since 1855. Both the grand vin and second wines are made from a blend of predominantly Cabernet Sauvignon, with Merlot, Cabernet Franc and Petit Verdot playing second fiddle. Château du Tertre sits on one of the highest geographical outcrops of the Médoc. It takes its name from this mound – "mound" being an English translation of "tertre". Here the soils are mostly gravel, which allows for excellent drainage as well some stress on the roots on the vines as they are forced to dig deeper for more nutrients and minerals. This soil type is typical of the Médoc, deposited by ancient glaciers that moved down the Atlantic coast and melted, leaving behind pebbles and gravelly soil. Tertre's vineyards are partially biodynamic, with more to be converted in the future. The wines – both the grand vin and second wine, Les Hauts du Tertre – are made in a very similar style; the difference being that the grand vin is made from older vines. The grapes are all hand-harvested and vinified in a mixture of wood, steel and concrete before being aged in French oak. Château du Tertre was one of the first estates in the Médoc to use small, egg-shaped concrete vats to vinify their wines. The estate believes that the use of these vats to vinify a portion of the production allows for minerality to be retained in the resulting wines. Château du Tertre is owned by the Helfrich family of Les Grands Chais de France, having acquired it from the Albada Jelgersma family in 2021. The latter had owned the estate since 1997.