Describe a foreign country you would like to visit

The country I'd most like to visit is Portugal, and specifically the north rather than Lisbon. What I know about it is a fairly random collection. I know it had a huge maritime empire and then more or less disappeared from world power for two centuries, which I find interesting — most countries in that position don't handle it gracefully. I know the food is heavily seafood-based, and that they eat a lot of salted cod, which is odd for a country with fresh fish everywhere. And I know the language is much harder than Spanish to understand spoken, even though it looks similar written. What would I do there? Mostly walk and eat, honestly. I'd want to go to Porto and then take a train up the Douro valley, because I've seen photographs of the terraced vineyards and they look like the rice terraces in Sa Pa built for a different crop. Why do I want to go? Partly the food and the walking. But the real reason is the decline. I'm curious what a country looks like when it stopped being important five hundred years ago and made peace with that. Vietnam is in the opposite phase — everything is being built, everyone is in a hurry. I'd like to see what the other end of that looks like. I think it might be reassuring.