Old Swan House is one of the largest houses in Chelsea. It was designed by the renowned Victorian architect Norman Shaw in 1875, and it continues to have commanding views over the River Thames towards Battersea Park from its second floor ballroom. A Grade II-listed house--which means it must be preserved by British law--this 19,000-square-foot home still has its brick exterior intact, as well as five principal bedrooms and 11 staff bedrooms, a dining room that seats 20, private terraces, a swimming pool complex with sauna and showers, a passenger lift, air conditioning, state-of-the-art security and hi-fi systems. Do not forget the cinema and parking for five cars.

Debenham House
Price: £29 million ($51 million)
Location: 8 Addison Road, Holland Park, London

Debenham House is a 22,000-square-foot property that is listed as Grade I, which means it is in the U.K.'s statutory list of buildings of special architectural interest. Built in 1906 and designed by Halsy Ricardo, this house is a mixture of the Arts and Crafts movement, neo-classical and Byzantine styles. Glazed tiles are used extensively inside this ten-bedroom, five-bathroom house. Some depict peacocks, eagles, flowers, galleons and mythical beasts. Many may have come from an assignment originally commissioned for the Russian czar's yacht Livadia, built in the 1870's. In addition, there is a covered walkway from the road, a front garden laid out in a formal Dutch style and an Orangery in the back garden, where there is also a croquet lawn and a coach house with two-bedroom suites. But it's not lacking in modern amenities: a swimming pool, Jacuzzi, sauna, gym and billiards room can all be found on the property.

17 Upper Phillimore Gardens
Price: £25 million ($44 million)
Location: Kensington, London

The property was used by the Kensington Preparatory School for Girls from 1941 until 1997. After extensive renovation, it is now a detached property with bags of character. This nine-bedroom, seven-bathroom house covers more than 18,000 square feet over five floors, with two dining rooms. There is even an eight-person passenger lift, indoor swimming pool, gym, sauna and steam room, while all lighting in the house is computerized. An underground tunnel connects the house to the three-vehicle garage, and outside there is a Japanese-inspired garden with a waterfall. The house is part of the Phillimore Estate, situated within the Kensington Conservation Area--an architecturally preserved, historical London suburb.

This new, 15,000-square-foot house on a half-acre features a 50-foot long ballroom, catering kitchen fitted out for banquets, cherrywood-paneled library and gentleman's study. This property has nine bedroom suites, all with Italian marble bathrooms, a sweeping oval staircase rising through three floors and a wood-paneled lift that takes six.

The leisure complex has a heated mosaic swimming pool, sauna, gym and a 12-person Turkish bath, which was modeled on the one in Toprak Mansions. And, like Thunderbirds, there is a vehicle lift that takes your car from the forecourt into the four-vehicle garage below.

Located near Ascot and bordering the 14th fairway of Wentworth course, Hanover House is a 2.3-acre property that was finished in 2003 and has yet to be occupied. Inside the 17,000-square-foot house are five bedroom suites including a second-floor penthouse. The home has under-floor heating, air conditioning, high-specification security and a ten-line telephone system with 17 extensions. The property also hosts an indoor swimming pool with Jacuzzi, steam shower and sauna, floodlit tennis court and landscaped gardens.

14 Charles Street
Price: £15 million ($26 million)
Location: Mayfair, London

A newly restored Mayfair mansion, right in the heart of central London, comes with a sense of grandeur--check out the double-height, galleried reception room with chandelier. This four-bedroom suite house covering 11,000 square feet has an impressive open staircase as well as a Mews House out back with three further bedroom suites. The house also comes with a 45-foot swimming pool and double garage. It also comes with a laid out 50-foot formal garden.

28 Cadogan Square
Price: £14 million ($25 million)
Location: Knightsbridge, London

This listed family house in one of the best residential areas in central London was designed by the well-known Victorian architect George Devey in 1886 for the Earl of Cadogan. It sits on the west side of this central London garden square with a mews house behind. In the 1950s, the house was severely modernized inside to create more space and a lighter feel. It now has nine bedrooms, four bathrooms, a roof terrace, patio garden and lift. The house had been passed down by descent, although when the present earl inherited the title and the estate, he remained in his Chelsea house. The Cadogan Estate office occupied the building, but they moved out in 1996, and the house was put up for sale. The property sits on the picturesque Cadogan Square, which has a communal two-acre garden incorporating a tennis court.

68 Cadogan Place
Price: £12 million ($21 million)
Location: Knightsbridge, Central London

This imposing 11-bedroom home also comes with its own Mews house. Mews houses were originally used for the horses and coachmen. It can now be used as a staff quarters. The Grade II-listed property has state-of-the-art technology with music systems integrated into the principal rooms. There's a swimming pool, gym and steam room, as well as extensive gardens behind. The house is also a few minutes walk from some of London's best amenities--Harvey Nichols, Harrods, Sloane Square for shopping, restaurants in Knightsbridge and nightlife on Kings Road.