Throughout its history, Croatia has existed under the influence of many different empires. The Greeks and the Romans once ruled here, the independent state of Venice was once in charge, then the Austro-Hungarian empire. Old family names such as Frankopan, Zrinski and Habsburg have ruled the country's regions or entirety, sometimes from fortifications used to fend off invasions by Bulgaria, Hungary, the Italians and the Ottomans. As a result, Croatia is littered with old city walls, pristinely preserved or ruined castles. Here are some of the best.