Chesil Beach from the hill above Fortuneswell, Portland Harbour is on the right.
The Isle of Portland is a 4 mile (6 km) long by 1.5 mile (2.4 km) wide limestone island in the English Channel. It is near Weymouth in Dorset. The island is connected to the mainland by a large pebble tombolo called Chesil Beach, and by the A354 road bridge to Weymouth.
The island makes up part of the Jurassic Coast World Heritage Site.
The island is home to two small towns, Fortuneswell and Easton, as well as the villages Weston and Southville.
Portland gives its name to one of the British Sea Areas.
In Thomas Hardy's Wessex the "Isle of Slingers" is based on Portland, with Street of Wells representing Fortuneswell and The Beal is Portland Bill.
Records of Portland being inhabited date back to the 13th century AD, and the island was known to the Romans as "Vindilis" and to local author Thomas Hardy "The Isle of Slingers", as it was alleged the inhabitants threw stones to keep strangers away.
Portland is the site of the earliest Viking raid recorded in the Anglo Saxon Chronicle, for the year 789.
Portland castle was built by Henry VIII in 1539 in response to attacks by France, and cost £4,964 to construct. The castle is one of the best preserved castles from this period of British history.
The island was home to a Royal Manor and much of the island was owned by the British Royal Family. It was the crown who opened many of the quarries which make Portland famous. After the Great Fire of London Christopher Wren used six million tons of white Portland limestone to rebuild much of the city, and some well known buildings which are built of the stone include St Paul's Cathedral in London and the headquarters of the United Nations in New York City. After World War I a dedicated quarry was opened to provide stone for the Whitehall Cenotaph and half a million gravestones. A further 800,000 gravestones were carved after World War II.
Portland harbour, at 2130 acres (9 km²), is one of the largest harbours in the world. The first stone was laid by Prince Albert in 1849, and the last by Albert Edward, Prince of Wales, in 1872. The breakwaters were constructed mainly by convicts, and 22 lost their lives during construction. The breakwaters contain 5,731,376 tons of stone and cost, in 1871, £1,167,852.
The island and its harbour were home to much of the Royal Navy during World War II, and because of this the island was heavily bombed. Much of the naval base closed at the end of the Cold War, and the Royal Naval Air Station closed in 1998. The island is still home to HM Prison Portland and HMYOI Portland, and the harbour contains Britain's only prison ship, HMP Weare.
The southern tip of the island, known as Portland Bill, is home to a lighthouse. Refurbished in 1996 the lighthouse is now entirely computer controlled. An earlier lighthouse stands slightly further inland and is used as a bird observatory by ornithologists.