Calling all curious minds—scientists, anthropologists, relentless tourists: Saturday, April 9th, is International Obscura Day, the day to "explore hidden treasures in your hometown," or so says Atlas Obscura, a website dedicated to public curiosities and esoterica. If you're the kind of person who appreciates public oddities every day of the year, tomorrow is icing on the cake. Celebrate Obscura Day in one of hundreds of locales—from Los Angeles to Sydney, from Berlin to Manila.