Pieces of one of the planes that crashed into the World Trade Center, a mangled antenna from the top of the North Tower, a wallet containing a Sainsbury's reward card, a fire truck with its cab shorn off.

These are some of the artefacts in the National September 11 Memorial Museum, set to open in New York on 21 May.

fire truck
Remains of a New York City Fire Department Ladder Company 3 truckAFP

By turns chilling and heartbreaking, the Ground Zero museum leads people on an unsettling journey through the 9/11 terror attacks. There are scenes of horror, including videos of the skyscrapers collapsing and people falling from them, but there also are symbols of heroism, ranging from damaged fire trucks to the wristwatch of one of the airline passengers who confronted the hijackers.

Visitors enter into an airy pavilion where the rusted tops of two of the World Trade Center's trident-shaped columns shoot upward. From there, museum-goers descend stairs and ramps, passing through a dark corridor filled with the voices of people remembering the day and past the battered "survivors' staircase" which hundreds used to escape the burning towers.

The entrance to the National September 11 Memorial Museum is dominated by two steel columns known as tridents, which formed part of the building's structural support
The entrance to the National September 11 Memorial Museum is dominated by two steel columns known as tridents, which formed part of the building's structural supportAFP
People walk into the museum, past the salvaged tridents from the World Trade Center
People walk into the museum, past the salvaged tridents from the World Trade CenterGetty
The Survivors' Stairs, remnants of a Vesey Street staircase on which many people escaped to the street on September 11
The Survivors' Stairs, remnants of a Vesey Street staircase on which many people escaped to the street on September 11Reuters
A decorated pillar from Ground Zero and the Slurry Wall - a surviving retaining wall of the original World Trade Center
A decorated pillar from Ground Zero and the Slurry Wall - a surviving retaining wall of the original World Trade CenterGetty

At the base level, amid remnants of the skyscrapers' foundations, galleries plunge visitors into the chaos of the attacks: fragments of planes, dust-covered shoes of those who fled the skyscrapers' collapse, damaged firefighters' helmets, and the sounds of emergency radio transmissions and office workers calling loved ones.

The project was marked by construction problems, financial squabbles and disputes over the appropriate way to honour the nearly 3,000 people killed in New York, Washington and the Pennsylvania countryside.

A New York Fire Department ambulance
A New York Fire Department ambulanceAFP
Surviving firefighter Dan Potter's fire helmet,worn on September 11
Surviving firefighter Dan Potter's fire helmet,worn on September 11Getty
An American flag recovered from the World Trade Center site
An American flag recovered from the World Trade Center siteGetty
A public phone from the World Trade Center
A public phone from the World Trade CenterReuters
A pair of glasses recovered from Ground Zero
A pair of glasses recovered from Ground ZeroGetty
Part of a television and radio antenna from the North Tower
Part of a television and radio antenna from the North TowerGetty
Pieces of American Airlines Flight 11, the first plane that crashed into the World Trade Center
Pieces of American Airlines Flight 11, the first plane that crashed into the World Trade CenterAFP
Cards, badges and mementoes of some of those killed at Ground Zero
Cards, badges and mementoes of some of those killed at Ground ZeroGetty
A recovery mask used by a burn victim from the attacks on September 11
A recovery mask used by a burn victim from the attacks on September 11Getty
An elevator motor from one of the buildings
An elevator motor from one of the buildingsGetty
Bicycles and a bike rack from the World Trade Center site
Bicycles and a bike rack from the World Trade Center siteAFP
A wall with a quote from Virgil and featuring 2,983 panels - one for each victim
A wall with a quote from Virgil and featuring 2,983 panels - one for each victimGetty