The city's finest harborside stroll is along the Eastern Prom Pathway, which wraps for about a mile along the waterfront beginning at the Casco Bay Lines ferry terminal (corner of Commercial and Franklin sts.). The paved pathway is suitable for walking or biking, and offers expansive views of the islands and boat traffic on the harbor. The pathway skirts the lower edge of the Eastern Promenade, a 68-acre hillside park with broad, grassy slopes extending down to the water. Tiny East End Beach is here, but the water is often off-limits for swimming (look for signs). The pathway continues on to Back Cove Pathway, a 3 1/2-mile loop around tidal Back Cove.
Atop Munjoy Hill (above the Eastern Promenade) is the distinctive Portland Observatory, 138 Congress St. (tel. 207/774-5561), a shingled tower dating from 1807 and used to signal the arrival of ships into port. Exhibits provide a quick glimpse of Portland past, but the real draw is the view of the city and harbor from the top. Open daily from Memorial Day to Columbus Day from 10am to 5pm; admission is $5 for adults ($4 for Portland residents) , $4 for children 6 to 16 ($2 for Portland residents), and free for children under 6.