There is a relatively recent programme of establishing memorials. The Girona cemetery has an imposing long metal memorial naming an unhappy number of local-born Republicans who are somewhere in unmarked graves, most being post-war executions - it's less than 10 years old. There's stuff about this to be read.
We went on an outing to the old France/Spain frontier between Portbou and Cerbère, which commands stunning views and offers various ghostly ex-border buildings. Low-key signage pointed us to some display materials on the refugee plight in 1939, a surviving Francoist memorial (these are very rare - it was pleasantly defaced with red paint), and a 2016 Catalan plaque commemorating the International Brigades.
No man is an island, entire of itself; every man is a piece of the continent, a part of the main. If a clod be washed away by the sea, Europe is the less, as well as if a promontory were, as well as if a manor of thy friend's or of thine own were: any man's death diminishes me, because I am involved in mankind, and therefore never send to know for whom the bells tolls; it tolls for thee.
John Donne, Devotions Upon Emergent Occasions, 1624
(I sang a bit of The Red Flag, but it seemed a little inadequate).