Touted to be the most expensive flat in the world, One Hyde Park penthouse is estimated at $200 million.

The most expensive penthouse apartments will feature bullet proof windows, purified air systems and “panic rooms” and everyone on site will have access to an underground passage leading to the nearby Mandarin Oriental hotel.

Alhougth the image is not real, but a computer representation, it does give a view of what it will look like when completed in 2010.