Fiction that takes place in Portugal

Hi all!

I've started travelling the last few years, and I've been buying myself a book as a souvenir. I look for.books that take place where I'm visiting and/or books by authors of where I'm visiting.

I'll be travelling to Portugal next month (mostly Lisbon, with a pit stop in Sintra and Porto) and was wondering if anyone has any recs. I know I can just Google, but I thought I'd ask here.

I'm primarily interested in fiction (with preference for 1900s on) but I'll try to be open and look into whatever is recommended here (except for Harry Potter – I know JK Rowling was inspired by Porto, but I don't support her and I'm not drawn to fantastical stories anyhow).