Advice on road trip Sintra to Douro Valley
 

Hello,
Planning a road trip from Sintra to Douro Valley first week of November with a one night stay somewhere along the way.
Would appreciate advice on where to spend the night. We prefer a quaint picturesque town with interesting sites. Looked at info on Coimbra and Aveiro (both sound very interesting) but we would like specific thoughts on other smaller towns also.
Thank you!