We were going to walk the full length of the Duero River, 750 from the source in central Spain to the Portuguese border along the GR14. This proved impossible due to the long distances between places to stay.
Instead we decided to start at the mouth of the Ebro River in the Mediterranean Sea and head west walking across Catalunya, Spain and Portugal to the Atlantic Ocean; well as much as we could walk with a few buses across the longest stages.
Then we discovered the Fishermen’s Trail in SW Portugal so added another 4 days and 75k.
Here’s the blog.