4 Secrets of Australia’s Most Famous Isthmus – Palm Beach

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WestHead Isthmus 2016Most of us don’t even know what an isthmus is! Even standing at West Head gazing over Broken Bay and Pittwater, few realise that famous, exclusive Palm Beach is one! An isthmus (also sometimes called a tombolo) is best imagined as the narrow stretch of land that bridges two larger land masses, in this case the Pittwater Peninsula and Ku-ring-gai Chase National Park’s Barrenjoey Headland.

Here are 4 surprising secrets about the view from West Head towards Palm Beach: 

  1. More than 10,000 years ago, Barrenjoey Headland was separated from the mainland by rising sea levels; but it was not separated from the Pittwater Peninsula!
  2. Barrenjoey Headland was actually part of the Lambert Peninsula, joined to West Head by a low saddle ridge. This ridge sunk beneath the water when sea levels rose and created treacherous underwater topography and shallow waters at the mouth of Pittwater. Evident on modern navigation charts, it’s this ridge that was, and remains, a natural barrier to Pittwater ever being a viable harbour to rival Port Jackson.
  3. Before the rising sea levels, Palm Beach did not exist. Lambert Peninsula and Pittwater Peninsula were most likely dissected by an ancient river flowing through what is now Pittwater. All this flooded as the sea rose. The Palm Beach isthmus that took its place is the result of thousands of years of sand deposits.
  4. Between 1879 and 1977, human activity and farming halved the isthmus’ height (from 10-12m to 5-6m above sea level). The historic photo below is from the early 1900s*. So just 30-40years ago, researchers worked to stabilise the sand with remedial work, planting of native dune flora and restricting vehicular access. The second photo shows how the isthmus looks today.

Palm Beach Isthmus 1900sNow standing around 100m above sea level, Ku-ring-gai Chase National Park’s Barrenjoey Headland is cosmopolitan Sydney’s northern-most tip. In its shadow is a carefully managed golf-course (established in 1920s at the isthmus’ northern end). Atop, is its bold, still operational, historic lighthouse, constructed in 1881, and neighboring light-keepers cottage. To learn more about Sydney OutBack’s Wilderness and Aboriginal Explorer Tour and Cruise, just click here.

Our tours are also part of Tourism Australia’s Indigenous Tourism Champions Program (ITCP), recognizing that we offer a quality experience that that meets the needs and expectations of international visitors.

Discover more at http://www.dailytelegraph.com.au/newslocal/northern-beaches/the-thin-strip-of-sand-the-binds-barrenjoey-head-to-the-mainland/news-story/b9bc298dbb7c0d70cdff73e63fa26218

* Historic photo of Palm Beach isthmus from the 1900s courtesy of Daily Telegraph in the article above.

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