The world's most expensive apartment buildings are officially finished. Some people paid $225 million for these houses, bringing the price up to $9,500 dollars per square foot.

The name of the apartment complex is One Hyde Park, which is made of four glass and metal buildings connected with each other. Designed by Rogers Stirk Harbour + Partners, they have huge windows with beautiful views to Hyde Park—which to me is one of the most beautiful city parks in the world—and Knightsbridge, in London. The owners—most of them Russian, Chinese and Arab—can move in their 80s-looking furniture, black silk sheets and smoke-mirrored tables today.