I lived in the middle of three stacked apartments in my early twenties, but had a stairway down to the outside which opened to my own patio. There was a groundhog we called 'Pete' or 'Petey' that lived under the patio, and it was always nice to see a bit of wildlife so close to the city. Even the landlord didn't seem to mind his presence. On several occasions, we would find Pete sunbathing on the very top roof, above the third story, with no discernable pathway for him to have climbed up there. This went on for years and no one witnessed his ascent. Only that he would be up there and find himself back down at some point. Pete was a good neighbor, I miss him.