This is perhaps the battlefield's best known landmark.
From the NPS brochure: "The fighting here was a key factor in McClellan's failure at Antietam. Called Burnside Bridge after the Union general whose troops were held off most of the day by a few hundred Georgia riflemen."
The large sycamore tree at the left end of the bridge is said to be the original witness tree that was here on September 17, 1862.