About the location
If you are nearby, Gljúfrafoss (or Gljúfrabúi) is definitely worth a visit, even if it's not that well known. You definitely need to protect your camera gear at this place, because there is a lot of spray within the canyon. If you walk inside it, it feels more like a cave, because the path is pretty narrow. You should probably wear waterproof shoes, if you want to visit this place.