Porto and Coimbra

We stayed 3 nights in Coimbra, it could probably have been two, but we were able to fill our time easily. I think if you are jetlagged I would go for two nights minimum. Be prepared to walk up even more hills than Lisbon.

There is a beautiful library at the university and there is quite a bit to see in a tour there if you are interested. There was a post last year about tickets
There is also a restaurant that i remember for some reason. It is part of a museum wtih spectacular views. I can't honestly remember if we went to the museum, but the restaurant was the Loggia. i think we only had lunch or a coffee there just for the views.

https://community.ricksteves.com/travel-forum/portugal/which-ticket-to-choose-when-visiting-coimbra-university

We spent two nights in Coimbra and felt it was sufficient. We had a rental car and arrived in town mid-afternoon, so had about 1.5 days to wander and see what we wanted to see.

There were a few places in Coimbra that only accepted cash.

Back in August 2019, my husband and I spent three nights in Coimbra. We were able to fill all our time. The real highlight of Coimbra was the old town. We spent some wonderful evenings just exploring.

Day 1 - Afternoon arrival via train from Porto

• Explored the old town
• Attended a Fado show

Day 2 - Full Day

• Spent the morning and part of the afternoon visiting Coimbra University sites (Royal Palace, Chapel of St. Michael, Biblioteca Joanina, Museu da Ciência)
• Lunch at Restaurante Universitario Colegio de Jesus (This is a university cafeteria. A great experience with delicious food!)
• Spent the rest of the afternoon at Museu Nacional de Machado de Castro

Day 3 - Full Day

• Visited Aqueduto de São Sebastião and Jardim Botânico on the east side of the river
• Crossed the Mondego River via the pedestrian only Pedro e Inês Bridge
• Visited Jardins da Quinta das Lágrimas and Convento de Santa Clara-a-Nova on the west side of the river

Day 4 - Left on morning train to Lisboa

In 2023 my wife and I visited Porto (4 nights) and Coimbra (2 nights). Our trip report might be useful reference (parts 1-3): https://community.ricksteves.com/travel-forum/trip-reports/trip-report-portugal-aug-sep-porto-coimbra-lisbon-then-to-spain

Without looking it up I think we did 3-4 nights in Coimbra. Nice place, don't see the Conimbriga Roman ruins nearby mentioned above. We were impressed.

I'm going to agree with those who recommended at least 3-4 nights in Coimbra. On my 2017 visit, I know I spent at least three nights there, though I'm fairly sure it was four, and I was glad to have done so. In fact I have allowed four nights in Coimbra for my return visit two months from now.