Stock Photo - Northeast Coastal Area, Adriatic Sea March 1990. The rough, hilly terrain and low mountains northeast of the Adriatic Sea are evident in this low-oblique, northeast-looking photograph. The eastern boundary of the Alps, shown along the western margin of the photograph, ends in northeastern Italy and northwestern Slovenia. The Istra Peninsula, the very large land mass extending southward into the Adriatic Sea, is bordered on the west by the Gulf of Venice (and the smaller Gulf of Trieste) and on the east by the Gulf of Kvarner. The boundaries of northeastern Italy (including the city of Trieste), Slovenia, and Croatia and the capital cities of Ljubljana (Slovenia) and Zagreb (Croatia) are not discernible at this scale. The offshore islands southeast of the peninsula belong to Croatia. Slovenia is almost land locked, except for a small corridor that extends between Italy and Croatia along the northwest coast of the Istra Peninsula. Many of the mountains contain dense forests (dark areas), whereas the mountain valleys appear light green and tan. Part of the coastal plain of northeastern Italy is visible along the western margin of the photograph.