Discover the inner sanctum of Freemason's Hall, see Napoleon's toothbrush, marvel at a hoax plaque hidden in plain sight on O'Connell Bridge, try George IV's footprints for size, venture into a Georgian time capsule on Henrietta Street, cross the bridge beneath which William Rowan Hamilton had his 'Eureka' moment, explore a 'museum' flat preserved exactly as it was almost 100 years ago, tune into the world of vintage radio in a Martello Tower, spot Dublin's subterranean river, or post your thoughts in a mystery letterbox ? Dublin offers endless opportunities for getting off the tourist grid - for peering into the city's fascinating past and present. All you need to know is where to look and who to ask for. Secret Dublin is an indispensable resource for those who thought they knew everything about the city, or who want to discover its hidden treasures. Skip the crowds and clichés, and really get beneath the city's skin ...