Collio is the guaranteed quality location extending to the northern hills area of the province of Gorizia, near the Slovenian border, it has about 1.400 hectares of specialized vineyards. The lands are made of stratified marlstone and sandstone from ocean origins, which were brought up to surface by the lifting of the seabed in ancient times. These marlstones easily disintegrate under the action of atmospherical agents, which first origin coarse topsoil, then becoming granular, and finally very delicate, making the land ideal for vine-growing after a few seasons. This situation has made vine-growing favourable since ancient times, as the system began taking place before the pre-Roman age and spreading later on during the years of the ancient Roman Empire. Wines became renowned and researched already by ancient European courts, and especially by the Serene Republic, as well as the imperial Hapsburg court which reigned struggling for these lands over a long period of time. Modern vinegrowing starts in Collio during the second-half of the past century, with the introduction of precious varieties of grapes for the production of French and German wine, which replaced some old less important vineyards. An important stage for vine-growing in Collio is represented by the Italian presidential decree passed on May 24, 1968 which recognized these wines with the Guaranteed Quality brand.