If you were planning to spend over $200-million for a home, a big back yard would be the very least of your infinite prerequisites. However, some of the world's billionaires don't hold a game of catch with the kids or an evening swing in the shade on their “top priority” lists.

This is undoubtedly the reason that penthouses are able to sell in the high millions. There's currently a penthouse suite at the Four Seasons Hotel going for $30,000 a night, but that doesn't come close to comparing to the £100,000,000 price tag of the Penthouses at One Hyde Park.

This is the most astounding part: Not only is there one penthouse selling for more than $200-million USD, but there are four of them. The currently-under-construction One Hyde Park complex in London, England will feature four main buildings, each with its own penthouse suite.

The penthouses don't exist yet - they're slated for completion in 2010 - but unlike other projects, like Tim Blixseth's Pinnacle, One Hyde Park doesn't seem to be falling through. Everything's on schedule as world renowned designer, Richard Rogers, continues to move forward.

These posh penthouses sitting atop London's newest skyscrapers will be the high-living neighbors to 82 other stylish apartments underneath. Over 40 of these apartments have already been sold to upscale clientele around the world for an average of $40-million per. One Hyde Park isn't planning to take kindly to intruders. Instead of your run-of-the-mill security guard with a beer gut and flashlight in tow, London's high-born towers will feature members of the British Special Forces (SAS) keeping a watchful guard over residents and property.

Obviously, only the world's richest people will be able to afford the 1/5th billion dollar price tag. As you can imagine, a person this wealthy is often the victim of attempted kidnappings for ransom. So besides the SAS full-time guard, the penthouses and apartments also feature bulletproof glass and iris (eye) scanners and other intense security measures to protect the residents. In case anything gets past the SAS guard, there are emergency exists leading to a series of underground tunnels for the apartment residents. For the penthouse residents, state-of-the-art panic rooms can be used in times of trouble.

As of yet, it's not clear what type of furnishings the penthouses with have, nor exactly how large they'll be. But for the complex itself, many details have been released, including news about the communal spas, squash courts, wine tasting rooms, restaurants, and more. Some of the rumored reports flying around about the penthouses state that the rooms will include huge, floor-to-ceiling refrigeration units and, obviously, 24-hour room service. For the price tag of $200-million, an on-call wait staff is the least One Hyde Park could do.