The Island of Lošinj is part of the Cres-Lošinj island group, which constitutes the western segment of the Kvarner’s islands inside the Kvarner Bay. The Kvarner Bay together with that of Trieste forms the most inland point of the Mediterranean Sea. The Cres-Lošinj island group extends in a northwest-southeast direction for 99 kilometres with a total area of 513 km², which comprises 16% of the total area of the Adriatic islands.
The west part of the Kvarner islands consists of the following islands: Cres (409 km²), Lošinj (75 km²) and smaller islands of Unije (17 km²), Ilovik (6 km²), Susak (4 km²), Vele Srakane (1 km²), and a series of smaller uninhabited islands. The islands of this archipelago form the natural bridge between Istria and Dalmatia.
This archipelago lies in the middle of the northern hemisphere because a part of it goes through the 45th degree of the northern latitude. The biggest part of the archipelago is in the sub-tropical zone of the southern half of the northern hemisphere, which influences its climate and the way of life of its inhabitants.
Lošinj is the 11th biggest island on the Adriatic Sea, 33 km long, with the width varying from 4,75 km in the north and middle of the island, to 0,25 km near the town of Mali Lošinj. The total coastline of the island is 112,7 km. The whole coastline abounds in attractive bays and coves, ideal for swimming and sunbathing.
Lošinj’s highest hill is the wooded hill of Osoršćica (588 m), which is some 10 kilometres long and stretches along the northern part of the island. On the island of Cres, which is generally higher than Lošinj, the highest hill is Sis (650 m). Cres has a freshwater lake - Vrana, which is a natural phenomenon. It is needless to say that so much drinking water on a karst island represents a real treasure. This enormous natural tank of fresh and healthy water contains more than 200 million m³ of water and supplies all the towns and villages on the islands with fresh drinking water.
Many, many years ago the island of Cres and Lošinj were one, only after the channel of Osor was excavated, probably during the Roman period, two islands emerged. Today a bridge connects the islands and in the geographically trafficable sense they form one unit.