Below are some facts about the nation's most popular monuments, according to The U.S. Government Printing Office.

4 million people visit the Arlington National Cemetery in Arlington, Va., annually, where there are 5,400 funerals conducted each year.

Each face on Mt. Rushmore in South Dakota is 60 feet tall.

The Statue of Liberty in New York is 151 feet tall.

The Washington Monument is 555 feet tall.

There are more than 58,200 names carved onto the Vietnam Veterans Memorial Wall in Washington. More than 1,000 are missing in action.