I stumbled upon this interesting slideshow about an enormous historic abandoned mansion that once stood in Pennsylvania. I think you'll find it intriguing, despite the fact that there is no sound. I wish I could have explored this building while it existed. Feel free to mess with the channel tags as you see fit.

From YT:

"This was one of the best mansions ever built in the USA. In 1938 it cost over 1 million dollars each year for the upkeep. It was abandoned for many years. Stotesbury's abandoned mansion was an awesome place. I spent my teenage years exploring the mansion and all of the three underground basements and abandoned gardens. If any you had a chance to visit the mansion please post and let me know."