See inside Eagle's Nest, the 42-acre New York Vanderbilt estate where a Gilded Age heir built his sprawling mansion

The entrance to Eagle's Nest. Gabbi Shaw/Business Insider Can you hear "The Last Great American Dynasty" playing in the distance?There are many historical mansions on Long Island, but only one was once owned by the legendary Vanderbilt family. The 42-acre estate of William Kissam Vanderbilt II, which included his summer "cottage" of Eagle's Nest, is now a museum that's open to the public.Eagle's Nest was first built in 1910 as a small cottage, but as William II spent more time there, it expanded until 1936, when a full redesign was finished: It had become a 24-room Spanish Revival mansion.William II spent time at Eagle's Nest until his death in 1944. His will stipulated that upon his wife Rosamund's death, the estate would be left to Suffolk County and become a museum, which it did after her death in 1947.The Vanderbilts are one of the best-known (and richest) families in American history — so much so that Bertha Russell, the main character on HBO's "The Gilded Age," is based on Alva Vanderbilt, William II's mother. In fact, a major plot line in season three is based on William II's sister, Consuelo Vanderbilt, marrying the Duke of Marlborough in 1895.As a fan of "The Gilded Age," I knew I had to check out Eagle's Nest — even if Larry Russell isn't really based on William II, I still needed to see the real mansion that his character might live in, so I visited in July 2025.The museum is open every day except Monday, and tours of the mansion are offered every day. Tickets for the museum range from $10 to $15, depending on the visitor's age, while a guided tour of the mansion is an additional $9.Here's what it was like to set foot in the home of a Vanderbilt. On the North Shore of Long Island, about 40 miles outside New York City, lies the Suffolk County Vanderbilt Museum. The outside wall of the Suffolk County Vanderbilt Museum. John Penney/Getty Images Inside the grounds are hiking trails, gardens, and a gift shop. A sign on the property. Gabbi Shaw/Business Insider There's also the Charles and Helen Reichert Planetarium, which holds multiple shows daily. The planetarium. Gabbi Shaw/Business Insider The biggest attraction, though, is Eagle's Nest, the 24-room mansion of William K. Vanderbilt II, the great-grandson of Cornelius Vanderbilt. The front of Eagle's Nest. Gabbi Shaw/Business Insider Before I toured the home, I visited the museum grounds. A pathway that led to the Rose Garden. Gabbi Shaw/Business Insider At the entrance stood a pair of stone eagles, which were taken from Grand Central Terminal. Cornelius Vanderbilt himself commissioned the train station. These statues were once at Grand Central. Gabbi Shaw/Business Insider One of the first things I did was head toward the Rose Garden; sadly, most of the roses had already bloomed. The Rose Garden. Gabbi Shaw/Business Insider But the landscaping was still immaculate. The Rose Garden. Gabbi Shaw/Business Insider Even if the roses were already gone, the views of the Long Island Sound were worth it. The view from the Rose Garden. Gabbi Shaw/Business Insider Then it was time to head over to Eagle's Nest. There were plenty of paths that led to Eagle's Nest. Gabbi Shaw/Business Insider Eagle's Nest was originally built in 1910 as a small cottage. It expanded over the next three decades to become this Spanish Revival-style mansion. A view from inside the courtyard. Gabbi Shaw/Business Insider The courtyard was set up for Shakespeare readings, which happen throughout the summer. The courtyard. Gabbi Shaw/Business Insider One side of the mansion is a natural history museum. The museum entrance. Gabbi Shaw/Business Insider The other side is preserved to be just as the Vanderbilts left it in the early 1900s. The entrance to the living quarters. Gabbi Shaw/Business Insider This was unlike any other historical mansion I've seen on Long Island, which are usually modeled on medieval castles or Tudor mansions. Eagle's Nest. Gabbi Shaw/Business Insider These cobblestones were taken from the streets of Greenwich Village in Manhattan before the streets were paved over. These cobblestones came from NYC. Gabbi Shaw/Business Insider Upon entering the home, the first thing you see is the staircase. It was imported from a Belgian castle. The entryway and staircase. Gabbi Shaw/Business Insider There are portraits of William II's family in the entryway. This is his father, William Kissam Vanderbilt. He ran an arena you may have heard of: Madison Square Garden. William K. Vanderbilt. Gabbi Shaw/Business Insider Pictured top right is William II's mother, Alva Vanderbilt. She inspired Carrie Coon's character, Bertha Russell, on "The Gilded Age." Portraits of William K. Vanderbilt II and Alva Vanderbilt. Gabbi Shaw/Business Insider The first room I saw was the dining room. The dining room. Gabbi Shaw/Business Insider The ceiling is constructed from Florida cedar, or Southern Red cedar. The ceiling in the dining room. Gabbi Shaw/Business Insider In the corner is a beautifully crafted fireplace. The floor tiles were imported from Portugal. The fireplace. Gabbi Shaw/Business Insider Next to the formal dining room is the butler's kitchen. At the height of William II's entertaining, 36 servants worked at Eagle's Nest. The butler's kitchen. Gabbi Shaw/Business Insider With a view as great as Eagle's Nest's, of course there's a screened-in veranda. One of the porches. Gabbi Shaw/Business Insider Off the veranda is the Portuguese sitting room, named for the ornate fireplace imported from Portugal. It was constructed in 1494. A sitting room. Gabbi Shaw/Business Insider Here's one of the guest rooms open for display. Each guest room had its own closet and bathroom. A guest room. Gabbi Shaw/Business Insider Then, it was time to go upstairs and view the rest of the mansion. The staircase leading to upstairs. Gabbi Shaw/Business Insider One upstairs sitting room was almost entirely covered in dark wood. It also housed a giant organ. The study. Gabbi Shaw/Business Insider A portrait of William II's sister Consuelo can be seen in this room, in the bottom left. She coined the term "heir and a spare," which she used to refer to her sons with her first husband. The study. Gabbi Shaw/Business Insider She was married to Charles Spencer-Churchill, the Duke of Marlborough. If their marriage didn't produce children, his title would've gone to his first cousin, Winston Churchill. Another guest room. Gabbi Shaw/Business Insider Here's one of the guest bathrooms at Eagle's Nest. Note the marbled walls and tub. A guest bathroom. Gabbi Shaw/Business Insider This was William II's bedroom. The room is bright, with beautiful views of the water — he probably had a great view of his 264-foot yacht, the Alva. William's bedroom. Gabbi Shaw/Business Insider In addition to loving the sea, William II was an avid race-car driver, naturalist, and golfer. Another view of William's bedroom. Gabbi Shaw/Business Insider His bed, seen here, was a to-scale replica of the bed of Napoleon Bonaparte. William's bed. Gabbi Shaw/Business Insider These buttons, right by his bed, were connected to the servant's staircase. He could summon his butler, and lock or unlock the servants' stairwell. This system was complex for the 1930s. Gabbi Shaw/Business Insider In his bathroom, nods to his love of the water included a large ship on the floor. He also had a shower, which was somewhat unusual for the time. William's bathroom. Gabbi Shaw/Business Insider To get to his wife's quarters, I had to pass through the breakfast room. The breakfast room. Gabbi Shaw/Business Insider Like the rest of the home, it had a lovely view of the water. The view from the breakfast room. Gabbi Shaw/Business Insider William II had two wives — this is how the bedroom looked when it was occupied by his second wife, Rosamond Lancaster Warburton. Rosamund's bedroom. Gabbi Shaw/Business Insider This is her changing room and bathroom. Rosamund's bathroom. Gabbi Shaw/Business Insider Rosamund's tub is made of rose marble — a nod from William II to his nickname for his wife. Rosamund's tub. Gabbi Shaw/Business Insider As I left the living quarters, I reached one of the entrances to the museum. This room is dedicated to William II's son, William K. Vanderbilt III. This room was dedicated to William's only son, who died in his 20s. Gabbi Shaw/Business Insider Inside were specimens collected by William II's son on a 1931 trip to Africa. See the crocodile in the bottom left? Gabbi Shaw/Business Insider The scenes reminded me of the American Museum of Natural History in New York City, which made sense — the same designer and taxidermist, William Belanske, did both. One of the exhibits. Gabbi Shaw/Business Insider This is a portrait of William III during a safari in 1931. He died two years later in a car crash at 26. William III on his trip. Gabbi Shaw/Business Insider While it was time to exit this wing, there was still the rest of the museum to see. The staircase. Gabbi Shaw/Business Insider The other half of the mansion is filled with specimens the elder William collected on his trips around the world. William II traveled around the world on his yacht. Gabbi Shaw/Business Insider There's also a miniature replica of his yacht, Alva. During World War II, he donated it to the US Navy, and it was renamed the USS Plymouth. It was sunk by U-boats in 1943. Ironically, the ship was both created and destroyed by Germans. Gabbi Shaw/Business Insider There are multiple rooms that are filled with sea creatures. William II himself discovered multiple species during his travels. There are multiple rooms like this. Gabbi Shaw/Business Insider Down a final set of stairs was a basement filled with more relics from William II's life. A piece of the Alva. Gabbi Shaw/Business Insider There were also two of his cars parked and awaiting a driver (and probably a tune-up). His two cars. Gabbi Shaw/Business Insider As I exited the home and crossed the courtyard, I was surprised to learn that there was even more to see. A hallway. Gabbi Shaw/Business Insider I followed a sign for even more "habitats." The museum continued. Gabbi Shaw/Business Insider I don't know what I was expecting, but it wasn't a giant whale shark hanging from the ceiling. This is reminiscent of the blue whale hanging from the ceiling at the American Museum of Natural History. Gabbi Shaw/Business Insider Another room was dedicated to large predators. It had a taxidermied lion and a tiger, but my favorite was the polar bear. The polar bear. Gabbi Shaw/Business Insider The exit brought me to the back of the house. I decided to go back to the central courtyard to see if I had missed anything. The side of the mansion. Gabbi Shaw/Business Insider And I had! There was a small doorway that led to Eagle's Nest's backyard. The way to the backyard. Gabbi Shaw/Business Insider The house was set on a hill, so the yard was multi-level. The backyard. Gabbi Shaw/Business Insider First, I walked to the right. The right side of the house. Gabbi Shaw/Business Insider There was a large reflecting pool. A reflecting pool. Gabbi Shaw/Business Insider Then I walked to the left and came across another fountain and some well-manicured hedges. The fountain and hedges. Gabbi Shaw/Business Insider But the main attraction was, once again, the view. The Long Island Sound. Gabbi Shaw/Business Insider The lawn was open, so I decided to trek down and see what structure at the bottom was. The saltwater pool. Gabbi Shaw/Business Insider To my surprise, it was a filled-in saltwater pool. The saltwater pool. Gabbi Shaw/Business Insider They'd even left the ladder in. The pool ladder was left behind. Gabbi Shaw/Business Insider There were also changing rooms. Changing rooms. Gabbi Shaw/Business Insider With that, I had seen almost everything the Vanderbilt Museum had to offer, with the exception of a few hiking trails. Another view of Eagle's Nest. Gabbi Shaw/Business Insider I left the museum with a greater understanding of the Vanderbilts — and ready for season four of "The Gilded Age" this fall. Eagle's Nest. Gabbi Shaw/Business Insider Read next Gabbi Shaw is a reporter on Business Insider's editorial partnerships team. She covers entertainment, travel, food, and lifestyle for Business Insider, and Insider Inc.'s partners, including MSN, Apple News, and Yahoo.She graduated from Tulane University in 2017 with a degree in public health and now lives in New York City. She can be reached on X or LinkedIn.Please send all inquiries, comments, or tips to gshaw@businessinsider.com.Selected stories:I traveled from New York City to Disney World and back in 24 hours. 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