Plitvice Lakes are considered by many as number one Croatia's nature attraction. It's visited by a million people each year. The nature preserve boasts spectacular views of 16 crystal clear cascading lakes and abundant flora and fauna with 1,000 species of plants, 140 types of birds and 40 mammals. Most people flock to the lakes in summer. However only in winter, you can witness a unique view of frozen Plitvice lakes that has been unofficially called one of Croatia's natural wonders.