Siding Spring Observatory

The Siding Spring Observatory (SSO) is the largest optical observatory in Australia and is an important site for astronomy, astrophysics and space science in Australia. Along with several active telescopes owned by the Australian National University, the site is home to the Anglo Australian Telescope (AAT), many international research telescopes and commercially operated telescopes and is known as Australia's foremost optical and infrared observatory.

Siding Spring is one of two key sites for the Research School of Astronomy and Astrophysics in Australia (RSAA). The site sits at the summit of Mt Woorut, NSW, and is set within the stunning National Heritage Listed Warrumbungle National Park, around 30 kilometres from the town of Coonabarabran.

The Siding Spring Observatory is located on Mount Woorut (at a height of 1165m) approximately 25 kilometres west of the town of Coonabarabran, NSW. Bordering the eastern edge of the Warrumbungle National Park. The ANU land holding covers an area of approximately 151 hectares and includes the Observatory Precinct on the summit of Mt Woorut as well as steep slopes to the north and south.

The location of the SSO and its extent of mid-sized telescopes is particularly valuable for institutional and commercial operators due to the lack of alternate facilities in this longitude.

  • Opened in 1964
  • owned by the Australian National University (ANU)
  • Situated 1,165 metres (3,822 ft) above sea level
  • Research carried out at SSO is varied, from probing the depths of the cosmos in search of 'Dark Energy' to searching the Milky Way for other planets and signs of life
  • selected by ANU from many other possible locations due to the dark and cloud free skies and the low risk of future light pollution

Have you seen something in the sky and would like to find out what it is? Why not Ask an Astronomer?

Visit us


As one of the most valuable observatory sites, Siding Spring has a lot to offer to its visitors. You will be able to find many informative and educational displays about telescopes and astronomy, with hands-on activities, augmented reality and multimedia presentations for the whole family in the Café and Visitor Centre. Visit Dark Sky Traveller to find out more about opening hours and tours for all ages


The Lodge - make a booking

The new Lodge offers 18 private ensuite double rooms, combined with a library, lounge and seminar room, offering spectacular views over the Warrumbungle National Park. Bookings can be made via the reservation request form

Please note that overnight accommodation offering is restricted for research activities on the site.


Siding Spring Observatory has a rich history and many notable discoveries. Discover our history

Aboriginal heritage values at Siding Spring

The Observatory is located on the traditional country of the Gamilaraay/Kamilaroi language group who have occupied this area for at least 20,000 years. A traditional travel route passes through the mountains, with the distinctive peaks used for navigation. Dreaming stories, ceremonies and art reveal that the Aboriginal people of Australia could have been the world's earliest astronomers. They used the stars to guide them, to track the seasons, and to ascertain the availability of certain foods.