British naturalist Roger Lovegrove, author of “Islands Beyond the Horizon: The Life of Twenty of the World’s Most Remote Places” (Oxford University), has a soft spot for harsh lands. Halfmoon Island in the Arctic Circle, he writes, “is God-forsaken beyond words and produces a brief shudder, but at the same time it has a strange allure.” Less typical is his description of Fernando de Noronha, 150 miles off the coast of Brazil, which sounds like something out of a travel brochure: “as near to tropical perfection as one can imagine.” Lovegrave is the perfect guide for the extremely adventurous armchair traveler.