The Camellia Greenhouse. Gabbi Shaw/Business Insider Coe Hall is a 65-room mansion that was built on the Gold Coast of Long Island, New York, in 1921. The home, built by insurance exec William Robertson Coe, is inside the Planting Fields Arboretum. The main house, along with its multiple greenhouses and gardens, is open to the public. In the village of Upper Brookville on Long Island, New York, you can step back 100 years. All you need to do is enter the Planting Fields Arboretum, a 409-acr...