Combat between the allied forces of World War I and Germany ended on Nov. 11, 1918. The date has been used by countries around the world to honor the sacrifices of its military members ever since; in the United States, Veterans Day is an occasion to honor all those who have served. Monday's commemorative events include wreath-laying ceremonies, concerts and more. And find more Washington Post Veterans Day coverage here.

World War II Memorial: A wreath laying-ceremony at the World War II Memorial begins at 9 a.m.

Arlington National Cemetery:  The national Veterans Day ceremony at Arlington National Cemetery begins at 11 a.m. and includes a wreath-laying ceremony at the Tomb of the Unknown Soldier. There are no tickets and the event is free and open to the public, but space is limited. Get there early, because once at capacity the entrance will be closed. Gates open at 8 a.m.

Air Force Memorial: A two-minute moment of silence and wreath-laying ceremony begin at 11 a.m.

Mount Vernon Estate & GardensThe Harmony Heritage Singers, an all-veteran barbershop chorus, perform at 11 a.m. followed by a wreath-laying ceremony at the tomb of George Washington at 2 p.m. Active-duty military members and veterans can visit Mount Vernon free of charge.

Navy Memorial: A wreath-laying ceremony will take place at the Lone Sailor statue at noon.

Vietnam Women's MemorialThe Vietnam Women's Memorial celebrates its 20th anniversary this year. Singer Jan Daley, who entertained for troops in Vietnam, will perform at 12:30 p.m., and female veterans will be at the memorial to tell their stories about the war.

Vietnam Veterans Memorial: Another wreath-laying ceremony, including several speakers and a color guard, will honor Vietnam War veterans at 1 p.m.

Women In Military Service For America Memorial: Also free and open to the public, a 3 p.m. ceremony at the memorial will include a keynote address and a wreath laying.

American Freedom Festival: The Patriot Center at George Mason University will host Lynyrd Skynyrd for a veterans tribute concert.

If you want to enter the Main Reading Room at the Library of Congress, Monday is one of the rare opportunities to do so. It's open to the public from 10 a.m. to 3 p.m. Find out more from the Washington Post's book guru, Ron Charles.