About 50 km west of Kassel is...
About 50 km west of Kassel is Bad Arolsen situated. It is a small & quiet town. It is situated in a very beautiful environment with a lot of walking & cycling possibilities.
Besides that, there is also the Schloss (Castle) which can be visited.
Take a look at the travelogues to see more.
Some more info can be found on BAD AROLSEN

Dürre Runde
Boats on the Fulda River in Kassel
Herkules Statue up hill
Königsstrasse