Where is the U.S. flag flown at night?

The U.S. flag is flown at night at certain designated locations, particularly those of significant historical and national importance, such as the Fort McHenry National Monument. This site is renowned for its role in the War of 1812, specifically during the Battle of Baltimore, where the sight of the flag inspired Francis Scott Key to write "The Star-Spangled Banner." The flag is illuminated during the night, which is in accordance with the U.S. Flag Code, which states that the flag should be displayed at night only if it is properly illuminated.

While schools, state capitol buildings, and public libraries may also display the flag during the day, they don't necessarily have a requirement or tradition of flying the flag at night. Fort McHenry, being a historic site, honors the significance of the flag with nighttime displays, making it the appropriate choice among the options provided.