London has long been one of the exclusive real estate capitals of the world. In fact, the world’s most expensive house was sold there. Houses aren’t the only expensive properties in London, though. The city also boasts the world’s most expensive apartment—and construction on it hasn’t even been finished!

The four penthouse apartments atop One Hyde Park, London’s newest and most luxurious address, sold well before the arrival of the new year. The building, developed by Candy & Candy and funded by Qatar’s foreign minister, will include eighty apartments designed by architect Richard Rogers. It will also feature communal spas, squash courts and even a private wine-tasting facility. The building will cost £1.5 billion (around $3 billion USD) to develop and Candy & Candy plan to have it finished sometime in 2010.

A computer-generated image of the world’s most expensive apartment.

One of the four penthouse apartments was sold for over £100 million (over $200 million at the time), making it the most expensive apartment in the world. Each of the four penthouses will have a number of security features, including bulletproof glass, panic rooms and access to an underground passage leading to a nearby hotel.

Other apartments in the building are going for an average of over £20 million (around $40,000,000).