The fortress of Briançon, which we entered by a narrow winding roadway round the western rampart, is the frontier fortress which guards the pass from Italy into France by the road over Mont Genèvre. It must always have been a strong place by nature, overlooking as it does the valley of the Durance on the one hand, and the mountain road from Italy on the other, while the river Clairée, running in a deep defile, cuts it off from the high ground to the south and east. The highest part of the town is the citadel, or Fort du Château, built upon a peak of rock on the site of the ancient castle. It was doubtless the nucleus round which the early town became clustered, until it filled the lower plateau to the verge of the walls and battlements. There being no room for the town to expand, the houses are closely packed together and squeezed up, as it were, so as to occupy the smallest possible space. The streets are narrow, dark, gloomy, and steep, being altogether impassable for carriages. The liveliest sight in the place is a stream of pure water, that rushes down an open conduit in the middle of the principal street, which is exceedingly steep and narrow. The town is sacrificed to the fortifications, which dominate everywhere. With the increasing range and power of cannon, they have been extended in all directions, until they occupy the flanks of the adjoining mountains and many of their summits, so that the original castle now forms but a comparatively insignificant part of the fortress. The most important part of the population is the soldiery--the red-trousered missionaries of "civilisation," according to the gospel of Louis Napoleon, published a short time before our visit.