Carinthian Lakes

Hi everyone, who fancies a long weekend trip to one of Carinthia's lakes starting end of August (stretching into the warm September)? I'll be traveling by train from Vienna. I'd love to explore Weissensee, Ossiachersee, Faaker See, or Millstätter See. Going for swims and also happy to rent bikes and cycle around the lake or explore the area. I'm 34, from Vienna, a non-smoker, easygoing, humorous, empathetic, considerate, and caring. I'd be happy if you're similar in nature. But I'm also open to other lakes in Austria, e.g., lakes in Salzkammergut (Attersee for example) with bike rentals and leisurely cycling around. Where else in Austria do you like to go for a short trip? Let me know. I'm open to ideas. I also enjoy hiking, for example.