We are flying into Frankfurt then staying in Imsbach for three days and want to take a 2-3 hour cruise on the Rhine river to see castles. Any recommendations on best sections of the river?
My favorite part of the river is between St. Goar and Bacharach - go by Loreley and see Pfalzgrafenstein up close. But that takes only 70 min from St. Goar, against the current, or 40 min the other way. If you want to extend your time on the river, start in Bingen and cruise down to St. Goar or Bacharach. You can find the K-D schedules here.
I would do the whole section between Bingen (left side) or Ruedesheim or Assmanshausen (right side) up to Boppard. This allows you to see about 40 castles in just a few hours.
Thanks so much for your suggestions!!