industry the most advanced and well developed of the former Yugoslav republics and is starting to gain interest in the world's wine market. Climate and geography Slovenia has a diverse geography which provides a wide variety of microclimates. It is bordered to the north by Austria, separated by the Alps. To the west is Italy and the Adriatic Sea, Hungary to the east and Croatia forms the southern border. The region has a continental climate with cold, dry winters and hot summer. The far western regions of the Littoral have some Mediterranean influence. Some common viticultural hazards in the region include spring frost, drought during the growing season and summertime hail. Many of Slovenia's vineyards are located in the foothills of the Julian Alps and Karawanks and the Pannonian Plain. The Drava and Sava Rivers are major influences in the Drava Valley and Lower Sava Valley, respectively. Wine-growing regions Slovenia has three main wine-growing regions () : the Littoral Region, encompassing the area of the traditional region of Slovene Littoral, the Lower Sava Region, which includes the Lower Sava Valley, the White Carniola, and the Lower Carniola, and the Drava Region, which includes the Drava Valley. The Littoral Region is Slovenia's most internationally known region. Though predominately a white wine producer, it is responsible for most of Slovenia's red wine production. Littoral Region The Littoral Wine-Growing Region () has two of Slovenia's most widely known and prominent wine districts, the Gorizia Hills (Goriška brda) and Koper districts. It is subdivided into four districts. The Brda district borders the Italian wine region of Friuli-Venezia Giulia with the Gorizia Hills Denominazione di origine controllata (DOC). This region was one of the first in Slovenia to make a concentrated attempt at establishing an international reputation for quality. The area is planted with international varieties of Merlot, Cabernet Sauvignon, Chardonnay, Sauvignon blanc, Pinot gris (Sivi Pinot), and Pinot noir (Modri Pinot) as well as Ribolla Gialla (Rebula), Refosco (Refošk) and Friulano. Brda is best known for its Rebula white wine and Merlot-Cabernet blends. The Koper district on the Istrian peninsula along the Adriatic coast is the warmest wine region in Slovenia. The Refosco and Malvazija grapes are the most widely planted in Koper. The Karst plateau district, located near the Italian city of Trieste, is known for the wine style Teran which is a very dark, highly acidic red wine made from Refosco planted