Asphalt was discovered at La Presta in the Val-de-Travers in the Canton of Neuchâtel in western Switzerland in 1711, although through the eighteenth century it was used almost entirely for medicinal purposes. It was applied to road-making from about 1812, and large-scale mining began in 1873. Asphalt from the Val-de-Travers was exported to many other countries, and mining continued until 1986. Galleries extended for 100 km. through the mountains and asphalt was brought to the surface by horses, the last of which retired in 1975, and by electric railways. A gallery extending for about 1 km. is open for guided tours, during which visitors can learn about the use of explosives, the drainage systems in the mines, and can see tools and equipment used by the miners. They can also taste ham cooked in asphalt, a dish unique to the Val-de-Travers.