Dappes ( Vallee Des Dappes), a valley about 4 m. long and 2 m. broad in the Swiss canton of Vaud, on the W. slope of the Jura mountains, 4,000 ft. above the level of the sea. A small stream from which the valley takes its name meanders through it. It is inhabited by 100 or 150 herdsmen. Without value as a territorial possession, this valley has obtained some importance as the most available military route from France to Savoy. In 1802 France annexed it, but Switzerland recovered possession in 1814 and maintained it, although the treaty of Vienna did not stipulate for its relinquishment by France. On several occasions France endeavored to regain the valley, but was stoutly resisted by the Swiss confederation. In 1861 the arrest of a Frenchman by order of the Swiss authorities threatened to bring on a conflict between France and Switzerland; but in December, 1862, an agreement was concluded by which Switzerland ceded to France that part of the valley which contains the road to the Col de la Faucille, and received from France a district of equal size.