Gabbi Shaw/Business Insider
- I took a tour of Long Island's Oheka Castle, an hour east of Manhattan.
- It's the second-largest private home in the US and was built in 1919.
- It's now a residence, hotel, restaurant, and events venue.
If you've ever read or seen "The Great Gatsby," you know 1920s New York was home to extravagant mansions with owners who hosted


