A very thoroughly-researched fiction book about the haenyeo women on Korea's Jeju island. I only really knew of Jeju as a popular vacation spot for Koreans (and foreign tourists too), but there's a lot of history there to unpack. From Japan's colonisation, the US taking over after WW2, to the horrific massacres that decimated the population - there's some heartwarming bits but it's not a fun book.
Also just learning about the haenyeo in general, who dived up to 20m to harvest abalone, octopus etc. and uniquely it was the women who brought home the money and the men that stayed home with the kids. (Although somehow it still seemed like the men had some of the power. Funny how that happens).