The Eastern Promenade Trail is a 1.8 mile one-way trail that starts at
the seaport in Portland and ends near the water treatment plant. Plan on
hiking 3.6 miles if you plan to do this whole trail out and back.
Along the trail are views of the boats in Portland's bay, views of the surrounding islands in the bay like Peaks island, Fort Levett, and Long Island. This is a fairly popular biking trail as well, so be mindful of bikers.
Along the northern section of the trail is a water treatment plant. This area isn't worth seeing unless you're just passing on through. You can shorten the trip by turning back around mile marker 1.4 or when you reach the railroad crossing on the trail.