Map in hand, park ranger Karlton Smith lays an index finger on one rectangular shape he trusts to orient visitors with their historic surroundings.
"This building's actually McDonald's," he says. "That's a good marker."
Seconds later, an outstretched arm points toward the modern-day structure as it stands in real life on Emmitsburg Road - across the street from where Smith stands on Cemetery Ridge, a chunk of land on which hundreds were killed and wounded during the Battle of Gettysburg.
The use of 20th-century developments as reference points is one way Smith said he has been able to help visitors better understand what happened here in 1863.
But it's a teaching method that could someday be considered passé.
For several years now, the Gettysburg National Military Park has been carrying out plans to "rehabilitate" some of the land within its 6,000-acre boundary.
This is an in depth piece on the history of the battlefied and it's preservation. If you visited Gettysburg as a child as I did, this article may inspire you to revist with your children.