Even the most expensive, extravagant homes can fall into disrepair without proper care.These mansions were likely worth the equivalent of millions of dollars when they were built.Years later, they sit abandoned in varying states of deterioration.Visit Business Insider's homepage for more stories.When they were built, these lavish homes were likely worth today's equivalent of millions of dollars. Now, they're falling apart.From a villa that's been sitting empty for 70 years on an island in upstate New York to a Gothic manor in Scotland, here are 11 abandoned mansions around the world that were likely once worth millions of dollars.SEE ALSO:Jeff Bezos reportedly dropped $165 million on a mansion that broke the LA real-estate record. Here are the 17 most expensive homes sold in the US over the past decade.DON'T MISS:Here's how much space $1,000 in rent will get you in 11 major US citiesThe Carleton Island Villa, a dilapidated mansion that sits on an island in Cape Vincent, New York, hasn't been inhabited for 70 years.Source: Realtor.comThe 11-bedroom mansion was constructed around 1895 for William O. Wyckoff, who made his fortune from the Remington firearm and typewriter company. Around the World War II Era, contractors went in and removed the interior and doors and windows.Source: Realtor.com, CurbedThe mansion is now for sale for $495,000 ' but whoever buys it will certainly need to spend much more than that on repairs and restoration.Source: Realtor.comThe Swannanoa mansion in Lyndhurst, Virginia, was built in 1912 by railroad millionaire James H. Dooley, who reportedly built it for his wife.Source: Atlas ObscuraWhen the couple passed away, the 52-room house was used as a country club for a time. Then, a scientist couple leased the mansion and turned it into a museum while continuing to live there until their deaths. Nobody has lived in the house since 1988.Source: Atlas ObscuraThe mansion is occasionally still open to the public for weddings and other events, but local residents have complained that the estate has been mismanaged and that its condition is deteriorating.Source: News LeaderThe Cambusnethan House in North Lanarkshire, Scotland, is one of the last remaining Gothic mansions in the country.Source: Register for ScotlandThe mansion was built in 1819 to replace an early 17th-century house that burned down in 1810. In the 1970s, the house was used for mock medieval banquets, but it was further damaged by fire in the 1980s.Source: Buildings at Risk Register for ScotlandCambusnethan House is on Scotland's Buildings at Risk Register at a "critical" risk level. A group called "Friends of Cambusnethan Priory" was established in 2014 to try to save the building from any further deterioration.Source: Canmore National Record of the Historic Environment, Friends of Cambusnethan PrioryLynnewood Hall, a 110-room, century-old Gilded Age palace just outside of Philadelphia, was designed by Horace Trumbauer in the late 1890s.Source: CurbedIt cost an estimated $200 million to build in today's dollars. Although it's still in relatively good condition, it could cost up to $40 million to restore the hall and its grounds to their former glory, according to David B. Rowland, president of the Old York Road Historical Society.Source: Terrain.orgDespite its state of disrepair, Lynnewood Hall is actually still worth millions ' in July 2019, it was listed for sale for $11 million. However, it has since been taken off the market.Source: Realtor.comPidhirtsi Castle in the Lviv region of Ukraine was built as a leisure home for a high-ranking Polish military commander between 1635 and 1640 by Italian architect Andrea dell'Aqua.Source: World Monuments FundThe mansion prospered for years, but in the 19th century, new owners took over and neglected the castle, so that by the end of World War II, it had massively deteriorated.Source: World Monuments FundPidhirtsi Castle has been damaged by fire and flooding over the years. The Lviv Art Gallery foundation aims to restore the mansion, but a lack of funds seems to have hampered progress. The foundation is calling for investors to help with the restoration while local students volunteer their time to try to repair the estate.Source: The Vintage NewsThe McNeal mansion, which sits along the Delaware River in New Jersey, was built by industrialist Andrew McNeal in 1890 after he founded a pipe plant and foundry.Source: Burlington County TimesU.S. Pipe bought the property in 1899 and used it as its headquarters until 1953, after which it was abandoned.Source: Burlington County TimesIn 2016, the city bought the property and approved a redevelopment plan for the mansion that might include a restoration of the Victorian home, but the plan has since stalled and the home continues to sit empty.Source: Burlington County TimesThis "Swingers Tiki Palace," as it was dubbed by one photographer, in Chattanooga, Tennessee, was built in 1972 by strip-club tycoon Billy Hull to be the ultimate party palace.Source: The New York Post,Abandoned SoutheastThe structure fell into decay after Hull was arrested for tax evasion. The now-abandoned mansion is known for its Playboy bunny pool and its dramatic history.Source: Abandoned SoutheastThe owner got 20 years in prison, and the mansion, including an empty pool, is also now home to graffiti.Source: The New York PostThe Villa de Vecchi, known as the "Ghost Mansion" of Italy, was built between 1854 and 1857. It was meant to be the summer home of a Count named Felix De Vecchi, who was head of the Italian National Guard. The home had all the modern amenities of the time, including indoor heating pipes and a large pressurized fountain.Source: Atlas ObscuraBut it was home to a mysterious family tragedy. In 1862, the Count killed himself after he came home and found his wife murdered and his daughter missing. Relatives continued to live at the mansion until World War II, but the mansion was left uninhabited by the 1960s. The home's grand piano is said to be played at night by "a ghostly entity."Source: Atlas ObscuraA 2002 avalanche destroyed nearby homes, but the once-lavish and now battered "Ghost Mansion" remains standing.Source: Atlas ObscuraThese ruins that resemble an ancient European castle actually sit just outside of Kansas City, Missouri, and are the results of a dream of businessman Robert Snyder, who wanted to build a European-style castle in Missouri.Source: Atlas ObscuraSnyder started building in 1905, but the next year he was killed in a car accident and never saw it finished. His sons took over construction and lived there until the family ran out of money because of several lands rights lawsuits surrounding the castle's property.Source: Atlas ObscuraAfter the youngest brother was forced to leave the home in poverty, it was turned into a hotel until 1942, when it was destroyed by a fire. In the 1970s, the state of Missouri bought the property and did some restoration work, but the former mansion remains largely in ruins.Source: Atlas ObscuraOn Pollepel Island in New York's Hudson River sits the Bannerman Castle. It was built by Scottish entrepreneur Francis Bannerman VI in 1901.Source: The New York TimesHowever, instead of using it as his home, Bannerman used the castle to store military weapons for his business.Source: The New York TimesAfter the powder house exploded in 1920, the upkeep of the castle dwindled. It was eventually acquired by the Hudson Highlands State Park Reserve.Source: The New York TimesIn 1992, the Bannerman Castle Trust was started in an attempt to repair the ruins. Since then, it has raised over $1 million to refurbish the castle, which is now open to the public for tours.Source: The New York TimesThe Pineheath House in Harrogate, England sat abandoned for 27 years.Source: IndependentIt was purchased in 2013 by a local businessman after spending over a quarter of a century untouched.Source: IndependentThe mansion dates back to the 1920s and was originally owned by wealthy aristocrats Sir Dhunjibhoy and Lady Bomanji.Source: Daily Mail,IndependentAfter Lady Bomanji died in 1986, the home remained untouched with the couple's items still scattered around.Source: Daily MailThe mansion was left to Lady Bomanji's daughter, Mrs. Mehroo Jehangir, who left the home as it was prior to her mother's death. She passed away in 2012.Source: Getty ImagesA doll that appears to have been left behind by the couple was found in one of the home's 40 bedrooms ...Source: Getty Images... and a playlist of songs was left in the ballroom.Source: Getty ImagesThe couple lived in the home during the colder months of the year and spent their summers at their home in Windsor, England.Source: Daily MailThe current owner has vowed to turn the mansion back into a luxury home.Source: Independent Click here to read full news..