This doghouse was Roscoes. When Ms M first got him, he was an adorable puppy. But as he grew his behavior, when left alone, caused her to have to relocate often. He would tear up her stuff if left inside alone. If left outside alone he would howl and bark incessantly, driving neighbors nuts. If given half a chance he'd escape his solitude to end up chased around the neighborhood by the dog catcher. She got him a dog run and he'd just howl his outrage at being behind bars. Then she and he boyfriend at the time made Roscoe the world's sturdiest dog house. The idea was to give Roscoe shelter that was so heavy that when leashed to it by a study cord attached to the doghouse, he'd be safe and have shelter. He was never happy with this dog house. He hated being leashed to a dog house he'd never go inside. He'd still howl and carry on, attempting to drag the dog house behind him as he tried to get away from it. So moving in with me was her last chance to find a way to keep Roscoe. He was always happy here, and there was never a need to chain him to his unused doghouse. So, the doghouse has remained empty. I think of it as a warning to possible intruders that you may not see the huge dog, but he sure has a very big doghouse, so buzz off.
Marly is the only dog to show an interest in it. No, she doesn't ever go inside and curl up like a contented dog, but she does poke around it now and then.