Eight years after the September 11 attacks, the final piece of design at Ground Zero has been unveiled: The underground museum linking the two reflecting pools  that will mark the footprints of the Twin Towers.
Designed by Davis Brody Bond Aedas, the underground structure is spare and unassuming--a passage, winding through the foundations o the original WTC complex, which will display remnants of the two towers.
The largest single piece on site, forming the museum's western wall, will be the original, 60-foot slurry wall , which held up amid the shock of the towers' fall--a symbol of resilience and strength. The wall had been preserved through mammoth efforts  to preserve and buttress the original remains.
The procession through the museum will descend through a series of exhibition halls, along a sloped, meandering ramp, which eventually opens up, to reveal a sweeping view of the bedrock footprints of the towers, precisely marked with metal walls. The path ends by passing by the "Survivor's Stair," which ferried hundreds to safety after the attacks. Also on display is the "Last Column "--the final piece removed from the WTC site, which served as an impromptu memorial and remains scrawled with remembrances left by rescue and recovery workers (you can see the column in the image above).
A view of the meandering ramp, and the walls that mark the original footprints of the towers:
Footprints of columns from the South tower, are visible in the floor:
Close-up of the slurry wall:
The stairs that begin the procession:
[Via Davis Brody Bond Aedas; renderings by Squared Design Lab]