Perched on the border of Hyde Park, this 19th-century mansion has been owned by a number of notable figures.

On London’s renowned Park Lane, one of the most recognized avenues in the city, there are two standalone houses, one of which is a magnificent property listed for £42.5 million (about $52.3 million). And for good reason—it’s the most significant home to be listed in the upscale Mayfair neighborhood in years, with intact period detailing and renowned previous owners. Constructed by Thomas Cundy II between 1857 and 1858, the Italianate-style palace was formerly occupied by the Marquess of Bristol and art dealer Henry Joseph Duveen, who catered to the likes of Andrew Mellon, J. P. Morgan, John D. Rockefeller, and William Randolph Hearst. 

The house, which has been completely renovated but has kept many of its original French Empire furnishings, faces the 350-acre Hyde Park. In 1906, Duveen, who frequently hosted some of the wealthiest people on the planet, hired William Henry Romaine-Walker, a private palace architect, to renovate the estate. Romaine-Walker built a large home out of the site, complete with a grand staircase made of marble in the manner of the French Empire, ceiling cornicing, and ornate wall moldings in the reception rooms, grand second-floor landing, and entry hall. He also included numerous marble fireplaces and stately Corinthian columns.

The home has undergone numerous changes over the years, including being used as a private office space in the middle of the 20th century, but it still has many of its amazing original features, including some of the most intricate cornicing in all of Mayfair, along with contemporary amenities and cutting-edge technology in every room.

Six bedrooms total in the 11,000 square foot house, with the main bedroom occupying a whole level with a view of Hyde Park. With a formal sitting area, two walk-in closets, an Arabescato Corchia marble fireplace, and a bathroom covered in Rosso Lavante marble, the main suite provides great solitude. The hydrotherapy bath has chromotherapy lighting and built-in wall mirrors and wall lights, and the steam shower is separate.

The top-floor penthouse-style bedroom suite boasts a vaulted ceiling with skylight windows, while the other rooms include marble en suite bathrooms and balconies. 

A formal dining room with French doors opening to the garden terrace, a wood-paneled study/library, four grand reception rooms, one with a custom cocktail bar with Baccarat crystal chandeliers and wall lights, temperature-controlled red and white wine cellars, an elevator, and a movie theater are all included. Up to 150 persons can be accommodated at once in the reception rooms. A garden terrace and authorized ideas for a rooftop garden are also present.

But it’s the facilities on the lower levels that take this home from exceptional to magnificent. A double-height gym, a juice bar, a steam room with a rainforest shower, a sauna with mood lighting, and a massage room are all located on the lower level. There’s also a 50-foot indoor pool, one of the biggest in Mayfair, and a hot tub with a mosaic floor. Hyde Park, Marble Arch, and Hyde Park Corner are depicted in an exquisite glass stairway that connects the pool level to the upper floor. 

Richard Cutt, associate director of Sotheby’s International Realty U.K., stated that “this mansion has the advantage of the lower ground and basement floors having an abundance of natural light introduced through the glass-roofed atrium, skylights, and lightwells to the various rooms, unlike many homes with basement extensions.”

Not a single detail has been overlooked. Cherry, oak, and maple wood are used to manufacture the doors and floors, while Jacaranda silk carpets are installed specifically for the bedrooms. Lastly, an app-controlled integrated Crestron system throughout the house manages the lighting, heating, cooling, pool and spa operations, smart doors, blinds, and home entertainment system. Each room has built-in speakers and a Sonos audio system, and the entire property is secured by a sophisticated security system.

“The largest-ever house sale on Park Lane would be a £42.5 million deal,” Wetherell’s founder and chairman Peter Wetherell stated. Such a large listing and transaction are very uncommon. Since 2006, this is the biggest and most significant house that has been up for sale on Park Lane. At that time, the neighboring Dudley House house on Park Lane was sold for £37.4 million to the Qatari Royal family as an office complex. Then, Formation Architects and interior designer Alberto Pinto turned Dudley House back into a private home. The Qatari Royal family owns the only two comparable Mayfair residences in the area, so you can see how significant the current sale is.