The old military fortifications at Middle Head seem weirdly out of place in Sydney Harbour's magnificent setting. Massive grey intrusions of brutal concrete hunker amid panoramas of glittering blue water and golden headlands. Narrow gun slits glare at the scenery as if denying its beauty.
Gun emplacements provide lines of sight across every angle of the harbour, useful in wartime and a big bonus to the peaceful sightseer today. Bring your camera, binoculars, picnic and folding chair, and settle in to enjoy some of the city's best scenery from clifftops cooled by refreshing sea breezes.
While you're at it, don't forget your hiking boots. Trails connect the fortifications across exhilarating stretches of water-hugging bushland, and several former military buildings have been converted into cafés for sustenance along the way.
With trails also leading to Balmoral Beach, clothing-optional Cobblers Beach and the family-friendly park and swimming area at Chowder Bay, you could take the day to explore.
It's extraordinary that these splendidly located historic sites are so little visited except by local residents. Walk past the current HMAS Penguin naval base and restored 19th-century officers' cottages on Middle Head and, beyond, you'll find yourself almost alone amid batteries and forts.
The oldest dates to the Napoleonic Wars, when Sydney was nervous of a French attack, but there are a whole string of structures dating through to World War II and beyond. The kids will have fun scrambling over gun pits and exploring the tiger cages used to train Vietnam War soldiers.
If you're keen on more detail, NSW National Parks runs occasional guided tours that explore the defensive structures, observation points and underground tunnels that honeycomb the headland.
Military history apart, you will enjoy a commanding position from which to squint across to Manly and Watsons Bay, and into the open Pacific Ocean beyond the harbour entrance. Further around the harbour at Georges Head, gun emplacements offer an even more dazzling view.
Not only can you see the outer harbour and heads, but down the harbour in the other direction to the city's skyscrapers, which rise behind the mansion-dotted hillside of Clifton Gardens. It's one of Sydney Harbour's most incredible views, yet always tourist free – even before coronavirus.
The walk from Middle Head to Georges Head along Chowder Bay Road leads you past more disused fortifications, tangled in undergrowth that hampers harbour views. About halfway along, you'll find a plaque that commemorates the Japanese midget submarine attack on Sydney Harbour in 1942.
Anti-submarine cables and mines stretched from Chowder Bay across the harbour between the 1890s to 1920s. Then the Army Maritime School took over until the land was opened up to the public 20 years ago. The sergeants' mess and submarine depot have been converted into cafés.
If you want to keep walking, a half-hour walk through a section of Sydney Harbour National Park will take you to Bradleys Head. It too is pockmarked with military installations, including a mid-19th century fort and bastion. The mast of the HMAS Sydney stands as a memorial to Australian ships and sailors lost in battle.
Sometimes you see more bush turkeys than humans, but the scenery is still amazing. Now the Opera House is in sight, and a great swathe of yacht-dotted, ferry-chugged harbour. The guns have gone, but those brilliant lines of sight remain.
A combination of buses 100 and 111 gets you from downtown to Middle Head. See transportnsw.info
The heritage Middle Head Officers Quarters features semi-detached cottages sleeping four. From $328 per night, minimum two-night stay. Phone 1300 072 757, see nswparks.info/middleheadquarters
The writer travelled at his own expense.