Data from CheapOair shows a huge spike in European destinations among travellers ages 18-25, and Croatia is among the top of the list. And for good reason! Small but bursting with geological diversity, there are no shortage of breathtaking sights. Start in the cultural hub of Zagreb, then make your way to Plitvice Lakes National Park (where caves, waterfalls, and sapphire lakes await), then head to Dubrovnik, where you can embark on a three-hour Game of Thrones walking tour.