Her Majesty’s secret doughnut

Britain’s spooks have a new haunt. This spring, the 4,000 spies, cryptographers, and other intelligence agents of the Government Communications Headquarters (the agency credited with cracking the Nazi’s Enigma code) move into a new 1.1 million-square-foot building in Cheltenham, 88 miles northwest of London. The Donut, as it’s being called, puts divisions once housed in 50 different buildings under one roof. Because of fears of terrorism, that roof – and the rest of the $634 million building – is pretty darn tough. "The building’s enclosed shape derives from ancient forts, where the inner space is secure and the outer wall is for defense," says architect Christopher Johnson, who headed up the project for his firm, Gensler. "Entering GCHQ is like entering Petra." For those without security clearance, here’s a tour of the bulwarks.

Postal Inspection
Packages get dropped off at the service center, x-rayed, and transported to the main building via an underground train.

Armor-Plated Rooftop
The roof, sheathed in a special aluminum, is designed to withstand airplane impacts.

Wiretap Central
A chamber under the interior courtyard shields the computer center, an 1,850-mile, billion-dollar network of fiber-optic cable that monitors email and phone calls around the world. It’s surrounded by a series of tunnels and shelters.

Stuctural Integrity
The round exterior forces shock waves from explosions to ripple around the building, diffusing as they go.

Tough skin
A one-story, 2-foot-thick concrete wall is topped with three stories of blast-proof glass.

Privacy windows
A second wall of glass, hung behind the first and composed of panels set at irregular angles, obscures views from outside.

– Jessie Scanlon

Pretty cool looking building!