Portland Harbour is located beside the Isle of Portland, Dorset, on the south coast of England. Construction of the harbour began in 1849; when completed in 1872, its 520-hectare (1,300-acre) surface area made it the largest human-made harbour in the world, and it remains one of the largest in the world today. It is naturally sheltered by Portland to the south, Chesil Beach to the west and mainland Dorset to the north. It consists of four breakwaters: two southern and two northern. These have a total length of 4.57 km (2.84 mi) and enclose approximately 1,000 ha of water.
Verne Citadel is a 19th-century citadel on the Isle of Portland, Dorset, England. Located on the highest point of Portland, Verne Hill, it sits in a commanding position overlooking Portland Harbour, which it was built to defend. It later became HM Prison The Verne in 1949.
Portland Castle is an artillery fort constructed by Henry VIII on the Isle of Portland, Dorset, between 1539 and 1541. It formed part of the King's Device programme to protect against invasion from France and the Holy Roman Empire, and defended the Portland Roads anchorage. The fan-shaped castle was built from Portland stone, with a curved central tower and a gun battery, flanked by two angular wings. Shortly after its construction it was armed with eleven artillery pieces, intended for use against enemy shipping, operating in partnership with its sister castle of Sandsfoot on the other side of the anchorage. During the English Civil War, Portland was taken by the Royalist supporters of King Charles I, and then survived two sieges before finally surrendering to Parliament in 1646.
East Weare Battery is a former 19th-century gun battery to the east of the Verne Citadel on the Isle of Portland in Dorset, England. The battery was built in the 1860s as a result of the Royal Commission to guard the new Portland harbour and Royal Navy institutions on the island. Five open batteries were built housing 20 9" and 10" RMLs. After 1877 the batteries were designated by letter 'A' to 'E'.
The Verne High Angle Battery is a former 19th-century gun battery on the Isle of Portland in Dorset, England. Situated close to the Verne Citadel, the battery is Grade II Listed, and forms part of the citadel's scheduled monument status. The battery has become a tourist attraction, while the battery's tunnels are often referred to by their local name 'Ghost Tunnels'.
The columbiad was a large-caliber, smoothbore, muzzle-loading cannon able to fire heavy projectiles at both high and low trajectories. This feature enabled the columbiad to fire solid shot or shell to long ranges, making it an excellent seacoast defense weapon for its day. Invented by Colonel George Bomford, United States Army, in 1811, columbiads were used in United States seacoast defense from the War of 1812 until the early years of the 20th century. Very few columbiads were used outside of the U.S. and Confederate Armies; nevertheless, the columbiad is considered by some as the inspiration for the later shell-only cannons developed by Frenchman Henri-Joseph Paixhans some 30 years later.
Fort Preble was a military fort in South Portland, Maine, United States, built in 1808 and progressively added to through 1906. The fort was active during all major wars from the War of 1812 through World War II. The fort was deactivated in 1950. It is now on the campus of Southern Maine Community College.
Fort Levett was a former U.S. Army fort built on Cushing Island, Maine, beginning in 1898. Located in Cumberland County, Maine, in Casco Bay near Portland, Maine, the fort was heavily fortified with guns for coastal defense. Conceived under the Endicott Program in 1885 and begun in the wake of the Spanish–American War, Fort Levett was manned during both world wars. It was part of the Coast Defenses of Portland, later renamed the Harbor Defenses of Portland, a command which protected Portland's port and naval anchorage 1904-1950. The fort's name is sometimes misspelled as "Fort Leavitt".
The RML 9-inch guns Mark I – Mark VI were large rifled muzzle-loading guns of the 1860s used as primary armament on smaller British ironclad battleships and secondary armament on larger battleships, and also ashore for coast defence. It should not be confused with the RML 9-inch Armstrong Gun, used by the Dutch navy, the Spanish Navy, and other navies.
Jewell Island is a small island in Casco Bay, Maine, United States. Approximately 1 mile (1.6 km) long from southwest to northeast, it is located off the coast of Cliff Island, approximately eight miles from downtown Portland. It is a state-owned island with a small but protected harbor as well as camping and walking paths. Jewell Island was part of the Harbor Defenses of Portland fort network. The island is part of the city of Portland. Jewell Island can be reached by private or charter boats. There is no ferry service to the island.
Fort Williams is a former United States Army fort in Cape Elizabeth, Maine which operated from 1872 to 1964. It was part of the Coast Defenses of Portland, later renamed the Harbor Defenses of Portland, a command which protected Portland's port and naval anchorage 1904–1950. After its closure, it was redeveloped into Fort Williams Park.
Fort McKinley is a former United States Army coastal defense fort on Great Diamond Island, Maine in Casco Bay, which operated from 1873 to 1947. It was named for President William McKinley. It included a sub-post, Fort Lyon, on Cow Island, just north of Great Diamond Island. Fort Lyon was named for Nathaniel Lyon. Both forts were part of the Coast Defenses of Portland, renamed the Harbor Defenses of Portland in 1925, a command which protected Portland's port and naval anchorage 1895-1950. In 1946 Fort Lyon was closed and turned over to the City of Portland. After Fort McKinley's closure it was transferred to the United States Navy, which sold the site to private interests in 1961. The Fort McKinley Historic District was listed on the National Register of Historic Places in 1985.
The 8th Coast Artillery Regiment was a Coast Artillery Corps regiment in the United States Army, which garrisoned the Harbor Defenses of Portland, Maine 1924–1944, and the Harbor Defenses of Portsmouth, New Hampshire 1924–1940.
Battery Steele is a United States military fortification on Peaks Island, Portland, Maine in Casco Bay. Completed in 1942 as part of World War II, it is located on 14 acres (5.7 ha) on the oceanside area of the island, formerly part of the Peaks Island Military Reservation. It is named for Harry L. Steele, who was a Coast Artillery officer during World War I. It was armed with two 16-inch MkIIMI guns and, with a 12-inch gun battery at Fort Levett on Cushing Island, replaced all previous heavy guns in the Harbor Defenses of Portland. It was built to protect Casco Bay, particularly Portland harbor, from Kennebunk to Popham Beach in Phippsburg. According to Kim MacIsaac and historian Joel Eastman in An Island at War, “Battery Steele is not only the largest gun battery built on Peaks Island, but also an example of the largest battery ever built anywhere in the United States.” In 1995, after decades of non-use, the Peaks Island Land Preserve, a community land preservation group, formed to purchase the area and forever preserve it as a public space. On October 20, 2005, the property was listed on the National Register of Historic Places. Other coast defense structures on the island include fire control towers and the counterweight for a disappearing searchlight tower.
The Portland Breakwater Fort is a 19th-century fort, built between 1868-1875 to defend Portland Harbour, Dorset, England. It is located on the outer breakwater of the harbour and has been Grade II Listed since 1978. The fort is not open to the public and remains derelict. On the opposite side of the next stretch of the breakwater is the Portland Breakwater Lighthouse.
East Weare Camp is a former 19th-century detention barracks on the Isle of Portland in Dorset, England. It is located at East Weares, overlooking Portland Harbour and East Weare Battery. The camp became Grade II Listed in 1978. Both East Weare Battery and East Weare Camp remain on the private property of Portland Port Ltd, and have not been opened to the public.
Verne Cistern is a water supply cistern on the Isle of Portland, Dorset, England. It is situated at the southern flank of the Verne Ramparts, on the slopes of Verne Hill, along the route of the horse drawn and cable operated Merchant's Railway - now a public footpath. It is on the edge of the Verne Citadel, a 19th-century fort, which is now HM Prison The Verne. The cistern became Grade II Listed in May 1993.
Verne Heavy Anti-Aircraft Battery is a World War II anti-aircraft battery on the Isle of Portland, Dorset, England. It is located on private property in the north-east area of the island, south of the Verne Citadel. The battery became a scheduled monument in March 2019.
The Harbor Defenses of Portland was a United States Army Coast Artillery Corps harbor defense command. It coordinated the coast defenses of Portland, Maine, the mouth of the Kennebec River, and surrounding areas from 1895 to 1950, beginning with the Endicott program. These included both coast artillery forts and underwater minefields. The command originated circa 1895 as the Portland Artillery District, was renamed Coast Defenses of Portland in 1913, and again renamed Harbor Defenses of Portland in 1925.
There are many Grade II listed buildings in the county of Dorset. This is a list of them.