Nicknamed the “The Expensive Billionaire Buildings” the ultra-luxury One57 tower, located at 157 West 57th St. in New York City recorded the most expensive purchase price in the state’s history in 2012: more than $90 million. The buyer of the 10,923-square-foot (1,012-square-meter) penthouse, which occupies both the 89th and 90th floors of the Midtown high-rise, remains shrouded in secrecy. The New York Post leaked that it was Sheik Hamad bin Jassim bin Jabar al-Thani, the prime minister of Qatar, but One57 spokespeople denied the rumor. Whoever bought the penthouse is getting quite a bargain, since it was originally listed at $115 million.

10. One57 Penthouse

Even though the One57 tower is still under construction, more than half of its 92 apartments are spoken for. The building will also be the home of the new Park Hyatt flagship hotel, and residents will benefit from the luxury hotel’s renowned service. The penthouse features 23-foot (7-meter) ceilings and glass curtain walls offering a panoramic view of Central Park below. Its sales price of roughly $8,000 per square foot was actually cheaper than the $13,000 per square foot Manhattan apartment bought by Russian billionaire Dmitry Rybolovlev, but that penthouse went for a paltry $88 million total.

9. Maison de l’Amitie

Believe it or not, the famous business tycoon known as “The Donald” ranks a lowly second on this list. But Trump’s beachfront property has skyrocketed in value over the years. He purchased the estate in 2004 from a bankruptcy court for $41.35 million. Maison de l’Amitie is the former home of Abe Gosman, an executive in the healthcare industry.

Trump put the house on the market in 2006 for $125 million but took a hit when the market collapsed. It was sold in 2008 to Russian businessman Dmitry Rybolovlev for a “measly” $95 million.

The 80,000 square feet (7,432 square meters) of Maison de l’Amitie feature a ballroom and a conservatory, 15 full bathrooms, and eight half-baths. Not to mention the 18 bedrooms spread throughout the main house, guest cottages, and tennis court. If the ocean is too salty for your taste, you can even take a dip in the 100-foot-long (30.4-meter) swimming pool.

8. William Randolph Hearst’s Mansion

The Hearst Mansion in Beverly Hills was the setting for the infamous scene in “The Godfather” in which a disloyal Hollywood movie producer wakes to find the severed head of his prize horse in bed with him. The mansion, formerly owned by publishing magnate William Randolph Hearst, is shaped like the letter H and features three pools as well as its own disco and movie theater. President John F. Kennedy stayed at the mansion during his honeymoon.

The Hearst Mansion shouldn’t be confused with Hearst Castle on Sunset Boulevard, located a little farther north along the coast. The castle contains 58 bedrooms, while the mansion has a mere 29. However, the castle is an established museum, no longer a private home and not for sale.

In 1947, Hearst bought the 1920s mansion and its 6-acre (2.4-hectare) estate for $120,000. In 2007, the estate’s current owner, attorney-investor Leonard M. Ross, put the home up for sale for $165 million. He took it off the market in 2008 when no one showed up with the trainload of cash needed to buy it. In 2010, Ross announced a drastically discounted listing price of $95 million, amid a bankruptcy filing, but as of December 2012, it was still available.

7. Silicon Valley Chateau

The exclusive Los Altos Hills neighborhood in Northern California is one of Silicon Valley’s wealthiest zip codes. The median home listing price in December 2012 was $3.8 million. But that’s pocket change compared with the $100 million that Russian billionaire Yuri Milner paid for his 25,000-square-foot (2,322-square-meter) French-style chateau in 2011. For the record, that’s a record. Before Milner, no one had ever paid $100 million for a single-family home in the United States. Which raises the question: How can a house with 14 bathrooms be considered a single-family home?

Milner, who is an investor in tech firms like Facebook, Groupon, and Zynga, bought the mansion, known as the Palo Alto Loire Chateau, for $50 million in cash. The other $50 million was financed through a personal loan from the sellers. The home is opulent by any standard; it’s modeled after an 18th-century French chateau and features indoor and outdoor pools, a ballroom, a 4,600-square-foot (427-square-meter) guest house, two three-car garages, and a private car wash. But even with all of those ritzy amenities, real estate experts believe that Milner wildly overpaid. The county tax assessor claims the house is only worth $50.27 million, half of what Milner forked over. That’s the kind of mistake only a billionaire can afford.

6. Fleur de Lys

Arguably the most expensive home in the United States, the Fleur de Lys in the exclusive Holmby Hills enclave of Los Angeles has been on the market since 2007. The price tag? An unapologetic $125 million.

The 15-bedroom, 45,000-square-foot (3,809-square-meter) mansion — which was inspired by the 17th-century French chateau Vaux-le-Vicomte (itself an inspiration for Louis XIV’s Versailles) — was built by Texas billionaires David and Suzanne Saperstein but ended up in Suzanne’s hands after a nasty divorce involving his affair with a Swedish nanny.

Among its authentic Francophile flourishes, the home’s exterior walls are covered with imported, handpicked French limestone. The interior is bedecked with 24-karat gold trim and museum-quality furniture, including Napoleon’s favorite chair and Marie Antoinette’s personal fire screen. If you get bored ogling the interior, you can always watch a Jean-Luc Godard flick in the 50-seat screening room.

5. Dracula’s Castle

Thanks to Vlad Tepes (better known as Vlad the Impaler, or Count Dracula), Bran Castle — built on 20 acres of a mountaintop in Brasov, Romania — became a museum in the 1980s. Legend has it the cruel count spent all of one night there. In 2007, the castle’s current owner, Archduke Dominic Habsburg, offered to sell the macabre museum to the Romanian government for $80 million, but the offer was rejected. Soon after, he announced that he would sell the castle in 2009 for an undisclosed price, although real estate experts projected a ballpark figure of $135 million. So far, no takers.

The castle was built in the late 14th century as a fortress to ward off invading Turks. The Habsburgs, Romania’s royal family, moved in in the 1920s. The castle boasts 57 rooms, including 17 bedrooms, decorated with handcrafted Old World antiques and furniture. Even if you don’t have the $135 million to buy Dracula’s former haunt, you can visit Bran Castle for only 25 Romanian lei (about U.S. $8). A photo fee is included, so don’t forget your novelty vampire teeth.

4. Elena Franchuk’s Victorian Villa

Elena Franchuk, a businesswoman and AIDS philanthropist from Ukraine, is reported to be the undisclosed buyer of a newly upgraded home in southwest London for 80 million pounds (approximately U.S. $129 million). The home is a freestanding, five-story, 10-bedroom Victorian villa, and underwent 10 million pounds (approximately U.S. $16 million) worth of upgrades, including the addition of an underground indoor swimming pool, movie theater, panic room, sauna, and gym.

The home served as a girl’s prep school until 1997. In 2006, developers purchased the property for 20 million pounds (U.S. $33 million). They put in the upgrades and reputedly sold it to Franchuk. The selling price broke the former English record for home sales of 67 million pounds (approximately $108 million).

3. The Penthouses at One Hyde Park

In 2011, Ukrainian oligarch Rinat Akhmetov bought the two top floors of one of the towers in One Hyde Park, London, for 140 million pounds or U.S. $214 million. This was the highest price ever paid for a residence in the U.K. The 17,000–square-foot (1,670-square-meter) penthouse apartments overlook London’s largest park and contain every luxury imaginable, from private gyms to his-and-her studies, and are reserved for the wealthiest of the wealthy. There are just 86 units in this ultra-exclusive London real estate development.

The “smaller” units in the development went on sale in 2007 for $20 million apiece. Despite shelling out all that cash, the apartments are apparently not luxurious enough. Akhmetov’s spokesman confirmed that he would spend an additional $90 million on renovations.

But you don’t just get a fancy address when you buy into One Hyde Park. Residents are protected by watchmen from the British SAS (Special Forces) and security features such as bullet-proof windows and iris scanners are the norm. The building itself has emergency exits leading to an underground tunnel to the nearby Mandarin Oriental Hotel, but the penthouse’s residents could simply run to their panic rooms if something happens. During less stressful times, One Hyde Park dwellers can bathe in communal spas, play on the squash courts, or drink wine in tasting rooms. If you don’t feel like cooking, the penthouses include 24-hour room service from the Mandarin Oriental Hotel.

2. Hariri’s London Mansion

In September 2012, British news outlets publicized the private sale of a London mansion that, if bought for its 300 million pounds ($484.51 million) asking price, would become the most expensive real estate transaction in the history of England. The 60,000-square-foot (18,288-square-meter) property, which overlooks London’s Hyde Park, was built by former Lebanese prime minister and self-made billionaire Rafik Hariri, who was assassinated in a Beirut bomb attack in 2005. Born the son of a humble Lebanese vegetable vendor, Hariri made his fortune in Saudi Arabia, where he developed ambitious real estate projects for the Saudi royal family.

The seven-story home has 45 bedrooms, and though it appears conservative and stately from the outside, inside reports claim the mansion contains millions of dollars of gold leaf, an industrial-sized kitchen, a swimming pool, and bullet-proof windows. Hariri built the mansion as four separate family houses, but it’s being sold as a single-family home, the largest such home in London next to Buckingham Palace.

The London market for extravagant real estate has boomed in recent years, with prices in the top 5 percent of the market jumping 49 percent since 2009. The 300 million pound asking price makes the Hyde Park mansion 815 times more expensive than the average London home, but that is likely to make the home even more desirable to the foreign billionaires who are seeking these trophy properties.

1. Antilia

The record for the most expensive house in the world was set in 2010 when Indian multibillionaire Mukesh Ambani and his family finished their $1 billion, 400,000 square foot (37,161 square meters) Mumbai home: Antilia. And at that price, it will likely hold the record for years. Named after a mythical Atlantic island, Antilia needs a staff of 600 to keep it humming. The building is 570 feet tall (174 meters) and made mostly of glass.

Forget going to the gym — the 27-story tower has its own health spa, yoga studio, and swimming pool. And the Ambanis’ friends can drop by in droves because the six-floor garage holds 168 cars. (Should any auto troubles develop, the in-house mechanics will take care of them). The ultra-modern high-rise also features a 50-seat movie theater, three helipads, dozens of balconies, and its own Hindu temple.

Mukesh Ambani is worth an estimated $22.3 billion, making him the 19th richest man in the world and the richest in India. That might explain why his new home has more floor space than Louis XIV’s palace at Versailles. And because most floors are double the average height, Antilia is technically 40 stories tall. The towering house isn’t too disconnected from nature; each level has lush gardens. It seems a refuge fit for a shy man referred to as “a modern-day Howard Hughes”. But some have criticized him for building such an opulent palace in a place as poor as Mumbai.