Where to birdwatch?

Dear all,

I hope you apologize for addressing you in English. I recently moved to Vienna (from Sweden) and I will live and work here for the next few years. I am a dedicated birdwatcher since 30 years focused on twitching and rare birds. Now I look for advice on where to go birding in Austria. Of course I know about Neusiedler Zee (probably wrong spelling) but I really need help in getting to the right sites. All suggestions are appreciated!

I look forward to your recommendations!

Best regards,
Magnus