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Grab a helmet to start your tour of Nottingham's caves

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And don't forget a torch... it's dark down there

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Watch your step as you head underground

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Chief executive Peter Armstrong expects at least 60,000 visitors in the first year

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There are models and displays throughout the caves

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Project manager Paul Baker demonstrates an air raid siren

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Don't panic - this World War II bomb is not live

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Expect a few unusual signs in the Nottingham caves

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The attraction has been renamed City of Caves