Bosnia. Dinaric Alps, Croatia; Bosnia-Herzecovina. A section of the rugged Dinaric Alps are visible in this south-looking view. The Dinaric Alps that extend 400 miles (645 km) along the coast of the Adriatic Sea, are composed of limestone and dolomite and are a barrier to travel from the coast to the interior; there are no natural passes. The partially submerged western part of the Dinaric Alps forms the numerous islands and harbors (upper portion of the image) along the Croatian coast. Sinkholes and caverns dominate the landscape. The region is sparsely populated and forestry and mining are the chief economic activities.[NASA]