Gettysburg National Military Park

Much of the area that saw one of the Civil War's most decisive and bloody battles (8000 killed in three days) is in this 8-sq-mile national park. The museum is a must-see, for the awe-inspiring cyclorama – a life-size, 360-degree painting – of a turning point in the melee. Paul Philippoteaux painted it in 1884, and, as of 2008, beautifully restored and installed with a compelling narration and light show.