Slovenian term for the special, iron-bearing soil type Terra Rossa. This is found in the Kras wine-growing area in the Slovenian region of Primorska and in the neighbouring Italian DOC area of Carso in the Friuli Venezia Giulia region as a continuous area. Both the Serbo-Croatian Kras (Engl. "thin soil") and the Italian Carso mean "Karst" and the names refer to the large, south-eastern European limestone highlands (see soil type in the "Karst" section). The special soil occurs there, however, only as a small area northeast of Trieste. The Slovenian-Italian border runs through the middle of this area. In Slovenia the red wine grown exclusively on this soil is called Kras Teran produced.
The much smaller Italian part covers only about 15 hectares within the DOC area Carso. Only wines grown on the Terra Rosso soil are allowed to be called Terrano here according to the grape variety used (the Terrano and Refošk varieties are identical). All others may only be marketed as Refosco. It is worth mentioning that the Italian side is also predominantly inhabited by Slovenian winegrowers, the current border was only drawn in 1954, and in 1986 a 15-kilometre-long wine route with 18 restaurants was opened, leading through the middle of the picturesque karst landscape. Also in Croatia, a red wine is produced from Refošk (Terrano), which used to be called "Istarski Teran" and today is mostly called just "Teran".