Berlin microcosm here?

Stadtgenossen!
Took next Friday off for Himmelfahrt and want to take a long weekends bike packing camping tour from Berlin on presumably my Kona Unit.
Still not 100% fit, arm and leg wise so relatively easy, max. 80km day, say, 3/4 days. Could be a loop, could be a short train ride out/in.
Still have Sacrow on my list so thinking of going south west.
Any leads on good routes or destinations?

Bumping this on the off chance