Croatia's rivers belong to the Adriatic and the Black Sea basin. The rivers in the interior are large and calmer (Sava, Drava, Danube).
The population of Croatia in 2003 was estimated by the United Nations at 4,428,000, which placed it as number 115 in population among the 193 nations of the world. In that year approximately 13% of the population was over 65 years of age, with another 20% of the population under 15 years of age.
Croatia's Catholic heritage can be seen in its celebration of Christmas, which falls on December 25 in Croatia. If you're in Croatia's capital city, do pay a visit to the Zagreb Christmas market, which appears, along with festive decorations, on the main square.