I visited a century-old New York mansion that was modeled after a medieval French castle. Take a closer look.

• Falaise is one of three 100-year-old mansions open to tour at Sands Point Preserve on Long Island.
• Falaise was built by Harry Guggenheim in 1923 and was modeled on a 13th-century French manor.
• Guggenheim lived there until his death in 1971, upon which the land was gifted to Nassau County.

Long Island’s North Shore is famous for being the inspiration for F. Scott Fitzgerald’s iconic novel “The Great Gatsby,” which took place in the fictional towns of West Egg and East Egg.

One hundred years later, some of the best-maintained examples of the mansions frequented by characters like Nick, Gatsby, Jordan, and Daisy are located in Sands Point Preserve, a 216-acre park that was once home to the Gould-Guggenheim Estate.

Inside Sands Point, there are four mansions. Three are open to the public: Falaise, Hempstead House, and Castle Gould. The remaining mansion, Mille Fleurs, is a private residence.

In September, I visited Sands Point to see Falaise, the most mysterious of the three — tours are only available on weekends and you can only get there via Sands Point’s transportation.

I paid $30 to visit ($15 to park and $15 for a tour), and I learned about its former owner, Harry Guggenheim, his passion for aviation, and his interest in art.

While I couldn’t take photographs inside the mansion — adding yet more mystery to the property — I was able to document its stunning exterior and European-inspired details.

Here’s what it was like to visit Harry Guggenheim’s summer home.