Get out and explore, but keep it within reason. Many of these places are full of asbestos and have begun collapsing. Without the right equipment and knowledge you run the risk of getting seriously sick, injured or worse. Getting the histoplasmosis lung infection from inhaling decades of bird shit in a tightly sealed space or falling through a weak floor is no good. Be curious, but always exercise caution too. I welcome your input and questions but please avoid contacting me for details on how to access these locations. Requests in this regard will have to be ignored in order to protect both you and I.