In fact, the Red Triangle boasts one of the greatest concentrations of these fearsome predators on Earth. And while attacks on humans off the Farallones are rare, scientists on the islands are all too aware of their deadly nature. Speaking to TV station NBC Bay Area in 2011 one researcher based in a lookout said, “You can tell shark attacks up here. Obviously if there’s blood, but also the gulls will start congregating.” Photo Credit: Reinhard Dirscherl/ullstein bild via Getty Images