The 1960s building that housed the U.S. embassy in London needed costly renovations and posed security risks in busy Mayfair, prompting a decision in 2007 to purchase a new site. Opening to the public on January 16, the new U.S. embassy resides in South London's Nine Elms area, below the Thames, where officials will unveil a "modern, welcoming, safe and energy efficient embassy for the 21st century."

Surrounded by a moat, the new embassy is a glass cube with hidden fortifications that cost about $1 billion, according to reports, making it the most expensive embassy in the world. Officials are quick to point out that the security demands of our post-9/11 world contributed to costs. 

The project was funded entirely by the proceeds of the sale of other U.S. Government properties in London.

Besides its impressive energy efficiency and environmental design, the new US embassy was planned by Philadelphia-based architects Kieran Timberlake with openness, diplomacy, functionality, security and value, in mind---along with large-scale art.

The US State Dept. program known as Art in Embassies, which employs art in cultural diplomacy outreach, commissioned some monumental works for the new embassy.

One piece is Rachel Whiteread's US Embassy (Flat pack house; 2013-1015), a wall sculpture at the entrance of the embassy, which is joined by works by such contemporary art luminaries as Sean Scully, Mark Bradford and Jenny Holzer.

The embassy's website says, "As it unfolds about the central core, the art can be experienced both within the major public spaces and from the outside as part of the continuum of spiraling walks and landscape form."

Each floor also features gardens, representing landscapes across America, from Pacific forests to the Gulf Coast.