Pretend you're a wealthy English lord in the middle of the 18th century. You've just gotten back from a Grand Tour of the Continent, and you want to keep the party going. How do you do that? You start up a not-so-secret club, and you build yourself a super cool underground cave fort for you and your friends to hang out in. Let's visit Sir Francis Dashwood's Hellfire Caves with our guide, Cieran O'Keeffe, host for 14 seasons of Most Haunted.