Traveling with kids can be fun, crazy and sometimes a little loud and chaotic. Even the most devoted parents occasionally want a few minutes… or hours… or perhaps even days of a peaceful child-free experience. Adults-only destinations and resorts are hardly a new concept, but over the last few years, a “no kids allowed” policy has been spreading beyond resorts to airplanes and, most recently, Viking Cruises. To get a feel for the current state of “no kids allowed,” here’s a list of major airlines, cruise lines and resorts that children aren’t allowed to travel. If you usually travel with...