Nothing is more frustrating than stumbling across an intriguing spot that's off-limits to all (or all but a select few). The antithesis of your average tourist trap, these places may even be steeped in local lore, but they often bar tourists for safety, security, or environmental reasons. Intrigued? We thought so. Here are 20 spots you'll have to admire from afar — if you're even allowed that close.
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