Along the internal belt of Bay of Kotor, from Morinj, across Risan to Kotor, the High-Karst Zone is in direct contact with the sea, as the High-Karst Zone overthrusts the Pindus Cukali Zone where Mount Orjen rises from the Bay of Risan. The direct contact of the Adriatic sea and the High-Karst Zone leads to interesting hydrological phenomena. In these terrains the largest vrulja on the Adriatic coast, called Sopot, is located. The vast differences in water-yielding capacity of the constant and periodic karst springs point out to the strong karstification of High-Karst Zone limestones and dolomites on Mount Orjen. The difference between minimal and maximal water yielding capacity is over 350 m³.