Cities are sized up by their architecture — more than the things that people talk about, like their weather or sports teams or politicians. Those are fleeting. Skyscrapers, schools, houses and libraries provide sustained, brick-and-mortar evidence about how interesting a place is and how much it cares about itself. Each year, Doors Open Denver gives all of us here an opportunity to self-reflect in that regard, to evaluate our own architectural ambitions — while, at the same time, allowing us to indulge our nosy natures.