Following the War of Spanish Succession, Austria once again developed interest in establishing a proper navy in order to protect its now numerous coastal possessions. This coincided with the majority of European nations' growing interest in mercantilism, the founding and development of colonies, and the chartering of overseas trading companies during the early 18th century. Austria's largest obstacle in engaging in overseas trade and naval enterprises however lay in the country's geography. Despite Austria having a lengthy coastline along the Adriatic Sea, the major ports it possessed along its main coastline were isolated from Vienna by the large Austrian Alps. Furthermore, there were no major rivers linking Austria's Adriatic ports to the interior of the country. Austria also enjoyed three major navigable rivers which flowed through the country, the Elbe, the Oder, and the Danube. However, the Elbe and the Oder flowed through the Kingdom of Prussia before emptying into the North and Baltic Sea respectively, while the mouth of the Danube lay within the territory of the Ottoman Empire. Both of these nations remained major rivals of Austria throughout the 18th century, preventing the Austrians from using its major rivers to gain access to the sea.