Carlos Hermosilla was born on Cerro Alegre in 1905. The rest you can learn here (if you speak Spanish, that is).
Anyway, there's currently a really decent expo of his work in the El Consejo Nacional de la Cultura y las Artes (click for more biographical info as well) down in Plaza Sotomayor. I'm not sure how much longer it's on for (I went over a week ago and then promptly forgot), so go as soon as you can. It's free. I'd never heard of him before wandering in but I really liked his stuff.
I only managed to take a couple of photos before being told off by the security guard.