Book excerpt: Alastair Bonnett explores extraordinary, off-grid, offbeat places including micro-nations, moving villages, secret cities, and no man's lands. Consider Sealand, an abandoned gun platform off the English coast that a British citizen claimed as his own sovereign nation, issuing passports and making his wife a princess. Or Baarle, a patchwork city of Dutch and Flemish enclaves where crossing the street can involve traversing national borders. Or Sandy Island, which appeared on maps well into 2012 despite the fact it never existed.