NEW YORK (AP) — The National September 11 Memorial Museum in Manhattan is opening to the general public on May 21.

Visitors will start in an airy pavilion. The rusted tops of two of the World Trade Center's columns shoot upward.

From there, museum-goers will descend stairs and ramps.

They'll go through a dark corridor filled with the voices of people remembering the day.

They'll also pass the battered "survivors' staircase" that hundreds used to escape the burning towers.

The galleries below contain more artifacts, by turns chilling and heartbreaking.