Every year on September 11, Americans commemorate the lives lost during the 2001 terrorist attacks on the United States. Four flights were hijacked that day and crashed into both of the World Trade Center’s twin towers, the Pentagon and an open field in rural Pennsylvania. Various memorials were erected during the years following the attacks, which stand as tributes to the victims, as well as symbols of the nation’s perseverance.

Continue on to view some of the public memorials built in honor of the victims of September 11, 2001.

National 9/11 Memorial Plaza | New York

Memorial Plaza opened to the public on September 12, 2011, and it features the names of the victims of attacks on the Pentagon, the four separate hijacked flights and the 1993 World Trade Center bombing. The commemorative area was built at ground zero of the 2001 World Trade Center attack.

Photography: Flickr

National 9/11 Pentagon Memorial | Arlington, Virginia

The benches pictured at the 9/11 Pentagon Memorial commemorate the 184 lives lost during the 2001 attack on the Pentagon. The names of victims are inscribed on these benches, which are arranged according to year of birth.

Photography: stayarlington.com

Flight 93 National Memorial | Shanksville, Pennsylvania

In Shanksville, Pennsylvania a 2,000-acre memorial dedicated to the victims aboard United Airlines flight 93 was constructed near its crash site. The flight, which was hijacked on September 11, 2001, and was headed for a destination in Washington D.C., crashed into an open field in Pennsylvania after passengers reportedly decided to rush the cabin and take control. Paul Murdoch Architects of Los Angeles, California along with Nelson Byrd Woltz Landscape Architects of Charlottesville, Virginia are responsible for the memorial’s design.

Photography: James Steakley

Postcards | New York

Postcards in Staten Island, New York was constructed to honor Staten Island residents who died during the September 11 attacks. Granite plates featuring the names and profiles of the victims line the large postcard-shaped structures.

Photography: statenisland.guide

The Empty Sky | Jersey City, New Jersey

The twin walls of the Empty Sky memorial are as long as the twin towers were high. Located in Liberty Park, New Jersey directly across from the Hudson River, the memorial commemorates 749 New Jersey residents that lost their lives during the September 11 attacks.

Photography: Chris Light

Logan Airport 9/11 Memorial | Boston

The Logan Airport 9/11 memorial pays tribute to the victims and airline staff aboard American Airlines flight 11 and United Airlines flight 175. Each of these airplanes was hijacked shortly after leaving the airport, and subsequently flown into the sides of the twin towers in Manhattan. The glass walls of the memorial display the names of the passengers and staff aboard the two flights.

Photography: Andrew Foeller

The Sphere | New York

The Sphere, originally created by German sculpture Fritz Koenig, was originally commissioned in 1966 by the Port Authority of New York and New Jersey. The sculpture stood in the Austin J. Tobin Plaza as a symbol of world peace through world trade until after the September 11 attacks, when it was recovered among the rubble at ground zero, relatively unscathed. The Sphere now resides in Liberty Park which overlooks the National September 11th Memorial & Museum.

Photography: Stephan Kambor-Wiesenberg

Tribute in Lights | New York

New York’s “Tribute in Lights” began in 2002 as a temporary memorial to the victims of the 9/11 attacks. Now held as an annual event, the marvelous spectacle is a dusk-to-dawn display of 88 searchlights positioned into two 48-foot squares, that mimic the shape and position of the Twin Towers.

Photography: Anthony Quintano