From bone-filled catacombs to hand-carved cave complexes large enough to house 20,000 people, this book is packed with more than 50 unusual destinations that take some digging to find. In the text, David Farley revels in the unexpected, whether it is a cave city in China which houses one of the world's largest collections of Buddhist art or an old salt mine converted into a theme park in Romania. Shown in color photographs, the points of interest here include Churchill's War Rooms, the Lascaux Caves, the Chunnel, the Vatican necropolis, and a three-story underground train station in Taiwan that is home to the largest glasswork on Earth.