AMBOISE, a town of France, in the former province of Touraine, now the department of the Indre and Loire, seated at the confluence of the rivers Loire and Masse. The town is the capital of a district, and has been rendered famous in history by the conspiracy of the Protestants in 1560, which opened the fatal wars of religion in France. The castle is situated on a craggy rock, extremely difficult of access, and the sides of which are almost perpendicular. At its foot flows the Loire, which is here crossed by a handsome wooden bridge with stone piers. To this fortress the duke of Guise, when he expected an insurrection among the Huguenots, removed Francis II., as being a place of perfect security. Only two detached parts of the ancient castle now remain, one of which was constructed by Charles VIII. and the other by Francis I. The former of these princes was born and died at Amboise. Pop. 4859. Manufactures, fire-arms, files, &c.