[masterslider id=”2″]
[tabby title=”Overview”]
Completed 2013
Designed by Terrence J. DeWan & Associates with Bruce John Riddell
Cliffside was the premier project of the Arboretum at Fort Williams Park. Its visibility along the north end of the Cliff Walk, exposure to onshore winds and salt-spray, and extreme level of infestation by invasive plants made it an ideal location to demonstrate the vision of the Arboretum. Initial clearing by volunteers of invasive vines and shrubs exposed beautiful trees and ledge outcrops, and opened awe-inspiring views of Casco Bay.
After a more thorough removal of invasive plants, pathways and steps were added to improve access, and stone walls were installed along with dozens of species of native and other beneficial plants, showcasing their ornamental potential in the landscape. As these plants mature and spread, they will provide increasing beauty and value as habitat for many species of pollinators and birds.
Members of the public help keep weeds and invasives in check and native species healthy through the volunteer Adopt-a-Plot program. This site is a favorite with Park visitors, who use it for picnics, yoga, weddings, and native plant identification.
Click here to download the Presentation Plan for Cliffside (pdf).
Click here to download the Cliffside Plant List (pdf).
[tabby title=”Historic Remnants”]
Historic Remnants
- Ammunition Magazine (1873): Built as part of an uncompleted battery, Ammunition Magazine is fully intact but buried under the hill to the left of the stone staircase leading up from the sidewalk.
- Mining Casemate (1891 / 1903 / 1944): Built into the side of the cliff on the south side of Ship Cove, its purpose was to control electric submarine mines in the main channels into Portland. It was used for local Civil Defense into the 1990s. Seen in front of the bottom of the steps are remains of the concrete mine tramway (with steel rails to the right).
- Battery Hobart (1898): Named for 1st Lt. Henry A. Hobart of the U.S. Light Artillery, it was the final battery built during the initial building phase at Fort Williams, and accommodated one 6-inch Quick-Firing Armstrong Rifle on a pedestal mount. Hobart was built into the uncompleted 1873 battery.
- Retaining Wall for Double Mine Station (1908): A wood-framed primary double mine station (demolished in 1973) stood in front of the concrete retaining wall between Battery Hobart and the buried magazine.
- Mine Wharf (1908): All that remain of Mine Wharf are the footings buried in high tide. The wharf was connected by a concrete tramway to a torpedo storehouse, cable tank, service dynamite room, mine loading room, and two cable huts (still extant).
- Tide Station (1909): To assist fire-control stations in their calculations, the tide station provided periodic readings of the height of the tide.
Please visit the Park History page for more information about Fort Williams’ military past.
[tabby title=”Plant Information”]
Featured Problematic Plant: Japanese knotweed (Fallopia japonica)
Japanese knotweed is an upright, shrub-like perennial that grows up to to 10 feet tall, with large, heart-shaped leaves in a zigzag arrangement along segmented stems (resembling bamboo), and creamy white flower clusters in mid- to late summer. Dying back to the ground after the first frost each fall, the foliage and stems turn a distinct golden amber in color and remain standing through winter. New asparagus-like shoots thrust from the ground each spring.
Introduced to the United States from eastern Asia in the late 19th century, it has since become highly invasive due to its ability to form a very deep taproot along with fast-growing rhizomes that enable it to rapidly colonize disturbed soils and form extensive and dense thickets, out-competing native vegetation. It grows most extensively in moist sites, but is also common along roadsides, parking lots and disturbed sites, and will even force its way up through paving and walls. Knotweed will regenerate from stem and root fragments, so it is easily transported to other sites where it will root in and grow.
Featured Beneficial Plant: serviceberry, shadbush (Amelanchier spp.)
Native to eastern North America, serviceberry is a highly varied and adaptable large shrub or small multi-stemmed tree with white, propeller-like flowers held in nodding clusters as the leaves emerge in early spring. The foliage turns attractive hues of apricot-orange to rusty red in late summer and early autumn. Naturally occurring in moist lowlands, rocky slopes and along the edge of woodlands, they are most prevalent in Fort Williams Park along the north-facing cliffs above Ship Cove, and in rocky outcrops along the Cliff Walk. Several trees were added to the Cliffside site during the 2012 planting.
One of the first woody plants to flower in spring, serviceberry is an important supplier of nectar and pollen for the earliest emerging bees and moths. The larvae of several butterfly species feed on its leaves, and it produces edible blueberry-like fruit in summer that is highly favorable to several species of birds and mammals. The fruit is often very sweet, and can be eaten fresh or dried, cooked for jams, or used in pies or to make wine.
Control Methods for Japanese knotweed

Adapted from Winning the War on Weeds: A Guide to Adaptive Invasive Plant Management, a publication of Maine Coast Heritage Trust
[tabbyending]

















