Gettysburg National Military Park covers 8 sq miles of land marked with monuments and trails. The museum at the visitor center is a must-see, particularly for the truly awe-inspiring cyclorama – a life-size, 360-degree painting – of Pickett's Charge, the especially lethal action on the war's last day. Originally made in 1884, the painting was restored and reinstalled in 2008.
Out in the park, you can explore on your own, on a bus tour or – most recommended – on a two-hour guide-led tour in your own car. From May to August rangers sometimes offer free guided tours as well. Sights of particular note include the Devil's Den, a boulder-strewn field that witnessed especially heavy fighting, and Little Round Top, a forested hill where men of of the 20th Maine staged an impossibly brave downhill charge that some historians credit with turning the tide of the battle.