This project features a glass-enclosed spiral staircase, a 16,100-sf (1,500-sm) glass wall and an 9,500-sf (880-sm) skylight. The building is reminiscent of a transparent snail’s shell revealing a staircase spiraling upwards through three levels. Each level contains foyers extending into the impressive glass body, which sweeps out like a huge convex sculpture. Berliners and visitors to the city have gained a new landmark of the highest quality, and after five years of construction, the German Historical Museum (DHM) now has its long-awaited extension with 29,000 sf (2,700 sm) of exhibition space.