The Maine Coast Heritage Trust, MDI High School and Acadia National Park maintain a group of trails adjacent to MDI High School in Bar Harbor.
My son was playing in a tennis tournament this morning and while he warmed up I explored the trails. The trails start behind the school as a dirt road next to two ponds. The trail then enters the forest and runs along the perimeter of NPS property. This was a nice quiet hike, relatively easy on a well worn path. One section of trail was closed to protect nesting raptors. On the return portion I spotted a deer in the woods.
The trail is well marked, with maps posted throughout. I hiked 1.4 miles but could have done more had I had more time.