The Eastern Bike Trail Green Velo
We particularly recommend the Northern Masuria Cycling Kingdom, which is a real "bicycle highway" combining the wildness of nature with beautiful landscapes and lots of attractions worth seeing.
You can find more information about The Eastern Bike Trail Green Velo and Northern Masuria Cycling Kingdom at the address: http://greenvelo.pl/portal/pl/krolestwa/polnocne-mazury
Have a nice trip!