Fort Denison is a popular attraction in Sydney Harbour near the Opera House with superb views in all directions across Sydney Harbour. Linked to Sydney's convict foundations, it is a former penal site and defensive facility occupying a small island north of the Royal Botanical Gardens .
The tower at the fort is one of only two surviving Martello Towers in the Southern hemisphere. The Fort gun is fired at one o'clock daily. it is part of Sydney Harbour National Park.

During the day Fort Denison is open for National Parks and Wildlife Service guided tours and can be hired exclusively for evening special events.

Things to do & see on Fort Denison

How to get to Fort Denison
Ferries departs wharf 6 at Circular Quay every 45mins, 7 days a week. Tickets include your return ferry from Circular Quay or Darling Harbour and Fort Denison Park Fee (excluding Martello Tower & guided tours).

Altenatively you can purchase an all-day Sydney Harbour Explorer Cruise ticket including Fort Denison Park Fee (excluding Martello Tower & guided tours). This cruise departs every 30-45 minutes and visits Darling Harbour, Circular Quay, Fort Denison, Taronga Zoo, Watsons Bay and Luna Park. Stop off at any destination throughout the day and reboard the next Explorer at your own pace. A great family day adventure.

After the first fleet arrived in 1788, Governor Phillip and his Advocate-General named it Rock Island. In 1788 a convict named Thomas Hill was sentenced to a week on bread and water in irons and the island came to be known as Pinchgut. Once a 15 metre (49 ft) high sandstone rock, the island was flattened as prisoners under the command of Captain George Barney, the civil engineer for the colony, quarried it for sandstone to construct nearby Circular Quay.

By 1796 the government had installed a gibbet on Pinchgut. The first convict to be hanged from the gibbet may have been Francis Morgan. In 1793 the British transported him to New South Wales for life as punishment for a murder. The authorities in NSW executed Morgan for bashing a man to death in Sydney on 18 October 1796.

In 1839, two American warships entered the harbour at night and circled Pinchgut Island. Concern with the threat of foreign attack caused the government to review the harbour's inner defences. Barney, who had earlier reported that Sydney's defences were inadequate, recommended that the government establish a fort on Pinchgut Island to help protect Sydney Harbour from attack by foreign vessels. Fortification of the island began in 1841 but was not completed. Construction resumed in 1855 because of fear of a Russian naval attack during the Crimean War, and was completed on 14 November 1857. The newly-built fort then took its current name from Sir William Thomas Denison, the Governor of New South Wales from 1855 to 1861.

The fortress features a distinctive Martello tower, the only one ever built in Australia and the last one ever constructed in the British Empire. Construction used 8,000 tonnes of sandstone from nearby Kurraba Point, Neutral Bay. The tower's walls are between 3.3 metres and 6.7 metres thick at the base and 2.7 metres thick at the top. However, developments in artillery rendered the fort largely obsolete by the time it was completed. The tower itself had quarters for a garrison of 24 soldiers and one officer. Fort Denison's armament included three 8-inch (200 mm) muzzle loaders in the tower, two 10-inch (25-cm) guns, one on a 360-degree traverse on the top of the tower and one in a bastion at the other end of the island, and twelve 32-pounder (15-kg) cannons in a battery between the base of the tower and the flanking bastion.

Eventually all the guns were removed, except for the three 8 inch (200 mm) muzzle loading cannons in the gun room in the tower, which were installed before construction was complete. The width of passages within the tower are too narrow to permit these to be removed. However, from the beginning the three cannons were of limited utility, for two reasons:

* The embrasures for the cannons were too small to use the guns effectively. By the time the cannon was loaded the ship would have sailed past.
* The recoil was too powerful for the small room.

In 1906, a saluting gun was transferred from Dawes Point to Fort Denison (see below).
In 1913 a lighthouse beacon built in Birmingham, England, and shipped to Sydney, replaced the 10-inch (25-cm) gun on the roof of the tower. In 2004 the NSW National Parks and Wildlife Service, which manages the site, restored the lighthouse beacon, which is still in use. The fort also has a still-functioning foghorn and a tide gauge room, which was established in the mid-1800s.

In May 1942, three Japanese two-man midget-submarines attacked Sydney Harbour. When the cruiser USS Chicago (CA-29) fired on the Japanese, some of its 5-inch (130 mm) shells hit Fort Denison, causing the tower minor damage that one can still see today.

Since 1992, the National Parks and Wildlife Service, which manages the site, has spent around A$2m conserving and upgrading the facilities.
Following publication of a Conservation Plan, further renovation commenced in 1999 and was completed in 2001. The conservation and adaptive re-use of the island was awarded the NSW Royal Australian Institute of Architects (RAIA) Conservation Award; a ŚCommendationą in the National RAIA Awards; and a National Trust Heritage Award in 2001.

Increased harbour traffic, coupled with the rising sea levels, has already destroyed the slipway. Furthermore, the porous sandstone drinks in the salt right down to the fort's foundations. In 2007 the government announced a $1.5 million rescue package.

Fort Denison is now a museum, tourist attraction, Sydney's only island cafe, and a popular location for wedding receptions and corporate events. The tourist facility contains an exhibition of the island's history from Aboriginal times.

NSW National Parks & Wildlife Services conducts tours, and operate a Harbour Navigational Facility, with tide gauge, navigation channel markers, foghorn and beacon.
The Bureau of Meteorology operates a weather facility from the island and publishes observations at half hourly intervals on their website.

At 1pm every day, Fort Denison's staff fire a cannon. This practice began in 1906 to enable sailors to set their ship's chronometers correctly. The daily gun continued until World War II when the authorities stopped it for fear of alarming residents. The practice recommenced in 1986.

Famous prank
In 1900, with the Boer war raging in Africa, White Star Line ship Medic sailed to Sydney ' Harbour and dropped anchor in Neutral Bay. One evening the fourth officer, Charles Lightoller and four midshipmen rowed to Fort Denison and climbed the tower with a plan to fool locals into believing a Boer raiding party was attacking Sydney. They hoisted a makeshift Boer flag on the lightning conductor and fired one of the cannons located at the fort.

The conservative citizens of Sydney frowned upon this activity and after an investigation Lightoller accepted sole responsibility for the incident and was reprimanded. White Star Lines apologised and paid damages to the city.

Charles Lightoller went on to be the second officer onboard RMS Titanic and the most senior officer to survive the 1912 sinking of the ship. He was a key witness at both the British and American inquiries into the disaster.

Popular culture
Fort Denison featured in the 1959 film The Siege Of Pinchgut, known in the United States as Four Desperate Men. Directed by Harry Watt, written by Jon Cleary and starring Aldo Ray, the film was the final film production of the British-based Ealing Studios.

It also featured as the base of operations for Neville Savage in the sixth episode of the Australian children's television show Mission Top Secret.

Abridged from Wikipedia and other sources.