The total area of the museum is 34,200 square metres. An exhibition entitled "600 years of Coastal Defence" is held permanently in the museum, which tells the story of the defence of the Hong Kong coastline from the time of the Ming Dynasty, through the Opium Wars and the Battle of Hong Kong, through to today.
On 8 December 1941, the Japanese launched their attacks on Hong Kong. After the fall of the New Territories and Kowloon, the British Forces immediately strengthened the defences at Lei Yue Mun to prevent the Japanese from crossing the Lei Yue Mun Channel from Devil's Peak. The defence forces managed to repulse several raids by the Japanese, but were eventually overwhelmed and the Fort fell into enemy hands on 19 December. The Fort no longer bore any defence significance in the post-war period, and became a training ground for the British Forces until 1987 when it was finally vacated.
The Museum consists of three main areas, namely the Reception area, the Redoubt, and the Historical Trail. It is converted from the hundred-year-old Lei Yue Mun Fort. Its historical structure has an extensive outdoor area with the unique architectural design, a strong tensile structure with other traditional building material, which provides a comfort and historical feeling for visitors.
The casemates inside the Redoubt were converted into exhibition galleries for permanent displays on the history of Hong Kong's Coastal Defence covering the Ming and Qing period, the British period, the Japanese invasion and the period after the resumption of Chinese sovereignty over Hong Kong.
Historical military structures in the site
- Redoubt: It was built in 1887 and formerly the core military structure of the Lei Yue Mun Fort.
- Central Battery: This battery was completed in March 1887. The gun barrel on the display is a 7 inch (17.8 cm) RML Mark 1 gun of 4.5 tons dating from the 1870s.
- Western Battery: Two 9 inch (23 cm) muzzle loading guns mounted in this battery in March 1887. The barrel displayed here, which was found in the Admiralty Garden site in 1990, alone weighed 12 tons.
- The torpedo station: The Brennan Torpedo station at Lei Yue Mun was built between 1892 and 1894. It was hewn out of the rock of the headland. It was the last to be constructed either in Britain or her overseas possessions.
- Lei Yue Mun Pass Battery: This battery was built to defend the harbour from destroyers carrying small, high speed torpedo and it was completed in March 1892.
The museum is open from 10 a.m. to 5 p.m. everyday except for Thursdays and the first two days of the Chinese New Year and the time for the last admission is 4:30 p.m.