Oheka Castle, the 127-room Long Island estate that inspired 'The Great Gatsby,' is heading to auction. Look inside.

An aerial view of Oheka Castle. J. Conrad Williams, Jr./Newsday RM/Getty Images Oheka Castle, the second-largest private home in the US, is headed to the auction block. The estate is said to have inspired "The Great Gatsby," and has been used in film and TV. It's also a favorite wedding venue for…