In looking over our itinerary for our France/Spain/Portugal extended road trip, I realize I have made a mistake in one of the bookings. We will be leaving Coimbra to head to Evora - and there is an unplanned extra day in between. This will be in mid September - and I can easily add a day to Coimbra (already have 4) or to Evora (also already have 4). In both places we plan to explore the surrounding countryside - and then we will be dropping the leased car at the airport after Evora and spending our final week in Lisbon.

Which would you choose for the extra day? And why?

You can’t go wrong with either choice.

We spent three nights in each and much preferred Coimbra over Evora. We could have done with one less night in Evora, but then again, we didn't have a car, so were unable to make easy day trips. Three nights in Coimbra was just right for us.

It all depends on what you have already seen. Alcobaça, Nazaré, Batalha, Tomar, Conimbriga are all with driving distance of Coimbra for a day trip.

https://flic.kr/p/2gx7RZP https://flic.kr/p/2gx9kaJ https://flic.kr/p/7Rnef6
From Evora you might want to visit the pre-historic sites and some of the hilltop villages like Monsarz and Estremoz.

https://flic.kr/p/2gqD2KJ https://flic.kr/p/2gpZrso https://flic.kr/p/2gqDZTF

I agree with Michael.