Ch¢teaux is the French word to describe a country or manor house. You would not therefore expect to find a ch¢teaux in a city. However, in Canada, a ch¢teau normally denotes a hotel and Ch¢teau Frontenac is the name for a very grand hotel in Quebec.

there are lots of famous vineyards, and not always big ones.
Some famous and very expensive wines (Château-Margaux, Château-Cheval-blanc, Petrus, Château-Lafitte-Rotchild, ...) are brand names and belong to a larger area. Château-Margaux is from the vineyard of Bordeaux for instance.
Renowned areas / vineyards in France: Bordeaux (with 'sub-regions' like Bergerac, Graves, Côtes de Blaye, Médoc, Pomerol....)
Bourgognes (sub-regions Côtes de Nuit, Côtes de Beaune, Beaujolais...)
and numerous others (link on French wines).

The population of Margaux is 1,479.

Margaux Billard is 5' 7".

Chateau Margaux is located in Margaux on the left bank of the Garonne estuary in the Medoc region. You can get more information about the Chateau Margaux at the Wikipedia.