rocky coastline
Acadia's Ocean Path runs from Sand Beach to Otter Point, providing a flat path as a starting point to stepping on to the rocky coastline. The section between Sand Beach and Thunder Hole tends to have a higher concentration of walkers while the sections near Otter Point are much quieter.
I prefer the quieter end, moving from the path to the rocks and back to the path again. It's a good trail for a brisk walk, and it's a good place for quiet contemplation.