http://bigguide.net/regional/Europe/Croatia/Big Internet guide with well over 4,000 quality Websites A Web guide to Croatia. Croatia borders the Danube river on the East, the Adriatic Sea on it's Southern border, and the Alps on the West. Croats are the majority of the population with Serbs, Slovenes, Hungarians, Bosnians, and others minorities continuing to move to Croatia.