Portugal

To better answer your question could you let us know when you will be going and how many days do you plan to spend in Lisbon and Porto.
Nazare is a good seaside town between Porto and Lisbon. It also has easy access to Obidos, Alcobaca, Batalha, and famous sights. There is enough to for a few days in Lisbon and Belem with no day trips or you could day trip to Sintra or Cascais. From Porto you could visit the Douro Valley, Guimaraes, and Braga, also depending on how many days you have as Porto has much to see and do itself.

Hi there: Thank you for getting back to me so soon! I will be in Portugal from July 6 to 21. I do not drive. I am waiting to rent apartments in both Lisbon and Porto. I am arriving from Madrid. All the best David G.

That certainly gives you time for more than Lisbon and Porto, although both are great destinations. Definitely day trip from Lisbon to Belem, Sintra and Estoril or Cascais. Probably Obidos as well. If you really want a coastal destination I'd look at Figueira da Foz or Viana do Castelo - Nazare looked very touristy the last time I saw it. But I'd really recomend Coimbra instead. Consider taking a trip up the Duoro valley from Porto - boat or train. I don't know whether the mountain railways are still running to Mirandela and Amarante, but if so they're worthwhile. I didn't make it all the way to Vila Nova de Foz Coa, but wish I had.

I would agree with Carol. Nazare is a very nice place. We were there in early May and wish we would have stayed more than just one day. The waves crashing on the beach are awesome!

Yes for sure see the Douro Valley outside of Porto. Nazare is a very nice seaside town to visit for the day.
If you can Obidos is a great village of historical signifiacanse, walled, well restored and a nice look at Portugal ancient past. Day trip works well.