With travel drastically curtailed and tourism down, the last few months have turned many Denver-area residents into amateur city-sleuthers. That’s because waves of Colorado- and Denver-centric travel books, and programs such as History Colorado’s “The Lost Book of Astrid Lee” scavenger hunt, have taken advantage of the pandemic (sometimes unintentionally) and spurred countless people to learn more about Colorado’s capital city. So what’s left to uncover? Plenty, according to Eric Peterson and David Lewis, co-authors of “Secret Denver: A Guide to the Weird, Wonderful and Obscure.” The book, published Sept.