@pv Lisbon and Porto, and then, on a smaller scale also Coimbra.
Porto and Coimbra have a river, Lisbon has the Atlantic Ocean.
Lisbon and Porto are wayyyy expensive, but if you come by Summer to Coimbra you won't find much activity, but at the same time it's the perfect spot to be for a couple of months to explore the country, because it's right in the middle of it, on the coast!
Either way, I'd start making connections before coming here. What kinda weirdos & hackers are we talking about?