Alcatraz Island

Where it sits. Alcatraz is a nine-hectare sandstone outcrop in San Francisco Bay, two kilometres north of the city waterfront and roughly the same distance from the Golden Gate. It has no natural soil, no fresh water and almost no shelter; everything on it, including the earth in its gardens, was carried out by boat. The currents around it run to several metres per second on the tide and the water sits between 10 and 14°C all year, which is the whole basis of its reputation. Juan Manuel de Ayala charted it in 1775 and named it for the pelicans nesting there, La Isla de los Alcatraces, and pelicans, cormorants and western gulls still hold the island in numbers that close parts of it every spring.

Four institutions on one rock. The island's history runs in layers. The first lighthouse on the west coast of the United States was lit here in 1854. A masonry fortification followed, mounting more than a hundred guns and holding Confederate sympathisers during the Civil War, after which the Army converted it permanently to a military prison in 1868 and used prisoner labour to build the great concrete cellhouse between 1910 and 1912 — at completion, the largest reinforced-concrete building in the world. The Department of Justice took it over in 1934 as a maximum-security federal penitentiary for men the rest of the system could not hold, and it ran in that role from 11 August 1934 until 21 March 1963. Then came the occupation: on 20 November 1969, a group calling itself Indians of All Tribes landed and claimed the island under a treaty provision covering surplus federal land, holding it for nineteen months until June 1971. Their painted slogans on the water tower and the dock buildings have been deliberately conserved.

The penitentiary years. B and C blocks held 336 cells, each about 1.5 by 2.7 metres, with a folding bunk, a basin and a toilet. The population averaged around 260 and never exceeded 302 — a small prison, expensive to run because everything from food to fuel arrived by barge, which is ultimately why it closed. Al Capone, George "Machine Gun" Kelly, Alvin Karpis and Robert Stroud were all held here. In May 1946, an escape attempt turned into the two-day Battle of Alcatraz, in which two officers and three inmates died and Marines fired rifle grenades through the roof of the cell block; the damage is still visible in D block. The escape everyone knows came on 11 June 1962, when Frank Morris and the brothers John and Clarence Anglin widened the ventilation openings at the back of their cells with sharpened spoons and a drill improvised from a vacuum motor, left papier-mâché heads with real hair in their bunks, climbed to the roof and launched a raft stitched from more than fifty rubber raincoats. They were never found. The case was formally open with the US Marshals for more than fifty years.

On screen. The films split into those made on the rock and those that only pretend to be.

• Escape from Alcatraz (1979) — Don Siegel filmed on the island itself with Clint Eastwood as Morris, one of the first features permitted to shoot in the cellhouse after it opened to the public
• The Rock (1996) — Michael Bay used the real cellhouse, shower room and Model Industries Building, while the flooded tunnels and other interiors were sets built off-island
• Birdman of Alcatraz (1962) — made almost entirely on sets, and misleading in a more basic way: Robert Stroud kept and studied his birds at Leavenworth in Kansas and was never allowed any on Alcatraz
• Point Blank (1967) — John Boorman opened the film on the island, in a derelict cellhouse only four years after closure

What a visit involves. Ferries leave from Alcatraz Landing at Pier 33 on the Embarcadero and take about fifteen minutes. The centrepiece is the Cellhouse Audio Tour, narrated by former officers and former inmates, which runs about forty-five minutes and is unusually good — it is built from oral history rather than script, and the voices frequently contradict each other. The walk from the dock to the cellhouse climbs the equivalent of thirteen storeys on a switchback road; a shuttle runs for those who need it. Beyond the prison, volunteers have restored the terraced gardens planted by staff families, and the island's western side is a seabird colony closed during nesting.

Getting there and timing. Tickets are sold only through the official concessionaire, are released around ninety days ahead and routinely sell out weeks in advance; the resellers outside Fisherman's Wharf are not a shortcut. Allow three hours door to door, more if you walk the whole island. September and October give the clearest air, summer brings fog that can obscure the city entirely from the dock, and the evening tour — fewer people, low light through the cell windows, the city coming on across the water — is the version most visitors wish they had chosen.