York County's Mill Creek Falls is one of Pennsylvania's most beautiful--and most accessible--waterfalls.
It's not too hard to find the Mill Creek Falls; you can see it from the parking lot. This is an ideal spot if you just need a quick fix of something beautiful.
From the road, follow the blue blazes of the Mason-Dixon Trail up the hill. After you admire and photograph the falls, consider hiking the roughly 2-mile loop through the woods for some tough climbs and gorgeous glimpses of the Susquehanna River.