The Dinaric Alps are one of the most rugged and extensive mountainous areas of Europe, alongside the Caucasus Mountains, Alps, Pyrenees, Carpathian Mountains and Scandinavian Mountains. They are formed largely of Mesozoic and Cenozoic sedimentary rocks of dolomite, limestone, sandstone and conglomerates formed by seas and lakes that once covered the area. During the Alpine earth movements that occurred 50-100 million years ago, immense lateral pressures folded and overthrust the rocks in a great arc around the old rigid block of the northeast. The main tectonic phase of the orogenesis in the area of the Dinaric Karst took place in Cenozoic Era (Paleogene) as a result of the Adriatic microplate (Adria) collision with Europe, and the process is still active. The Dinaric Alps were thrown up in more or less parallel ranges, stretching like necklaces from the Julian Alps as far as northern Albania and Kosovo, where the mountainous terrain subsides to make way for the waters of the Drin River and the plains of Kosovo.