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 lavish parties.
One of those owners was financier Otto Hermann Kahn, who built Oheka Castle — named after its owner (Oh-He-Ka) — on Long Island in 1919.