Opposite Belleville-sur-Saône is Montmerle. In the middle ages it was one of the sentinel cities which guarded the Principality of Dombes. Sieges and assaults without number were its portion, from the Bourguignons, the troops of the Sire de Beaujeau, the Dauphinois and the Counts and Dukes of Savoy. The imposing ruins of the former chateau-fortress tell the story of its mighty struggle which endured for nearly a century. For the most part the bulk of the material of which it was built has disappeared, or at least has been built up into other works, but the massive signal tower which once bolstered up the main portal still rises high above the waters of the Saône. The tower supposedly dates from the twelfth century--the period to which belonged the chateau--and is distinguished by its hardiness and height rather than for its solidity and massiveness. At Farcins, near-by, is a magnificent and still habitable chateau of the end of the reign of Henri IV, built by Jean de Sève, Conseiller du Roi, on the plans of Baptiste Androuet du Cerceau. From Montmerle one may see the towers and roofs of half a dozen other minor chateaux of the seventeenth and eighteenth centuries scattered here and there through the Beaujolais, but nothing distinctive arrests one's attention until Villefranche and Trévoux are reached. The Sires de Beaujeau, from motives of policy if from no other, ever respected the privilege of Villefranche (founded by Humbert IV). The traditions of Villefranche's old Auberge du Mouton are classic, and have been used time and again by playwright and novelist without even acknowledgment to history. It was here in the "Free City" beside the Rhone that Edward II swore to observe the city's claims of municipal liberty. Villefranche has no other notable monuments save the Hôtel de Ville of to-day, which is an admirable Renaissance town house, and another equally striking in the Rue Nationale. The latter is almost palatial in its proportions. Just below Villefranche is Trévoux, the ancient capital of the Principality of Dombes. It comes into the lime-light here only because of its ruined castle on a height above the town which travellers by road or rail cannot fail to remark even if they do not think it worth while to become intimately acquainted.