“Witness,” Peter Weir’s paean to rural Pennsylvania, put Amish country on the map. But in the process, it almost killed it. Since the 1985 film, Lancaster County’s population has grown by about 40 percent to approximately half a million. In the ensuing decades, it has struggled to protect its Amish and Mennonite residents and its achingly beautiful landscape. Surrounded today by its own mini-Beltway, the town that welcomed German dissenters in 1729, served briefly as the U.S. capital and put shoofly pie on the map is a bustling small city. Yes, stroll the well-kept town center. Shop at the Central Market, a tradition since 1730; it’s the place where the cliche “farm-fresh” could have originated. Visit the Fulton Theatre, an 1852 gem that roared back from the early pandemic with a new live season. But for a taste of Pennsylvania Dutch tranquility, head north this spring.