Hunter Bases are very similar to the Fisk contruction sites in the first Spider-Man: they are enclaves of enemies that you can web up and thump in the nose. You can do this stealthily, or you can go in spoiling for a brawl. After Kraven makes his appearence in the story, these bases will appear on the map. Complete all of these bases, and you will unlock this trophy.

The bases look like this: