In collaboration with the
International Astronomical Union
latest news
  • Chankillo has been inscribed on the World Heritage List...
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Find Astronomical Heritage
Locate astronomical heritage geographically and/or temporally
Locate (or submit) Places connected to the Sky

Welcome to the integrated web portal set up to serve UNESCO’s Astronomy and World Heritage Initiative, maintained by the International Working Group on Astronomy and World Heritage, and supported by the International Astronomical Union through its Commission C4 on World Heritage and Astronomy. The Portal to the Heritage of Astronomy exists to raise awareness of the importance of astronomical heritage worldwide and to facilitate efforts to identify, protect and preserve such heritage for the benefit of humankind, both now and in the future.

What is astronomical heritage?

Cultural heritage related to the sky is a vital component of cultural heritage in general.
Why preserve it?
What is the purpose of this web portal?


Astronomy and world heritage

This portal was set up to support UNESCO’s Astronomy and World Heritage Initiative (AWHI) and continues to provide thematic essays, case studies and general information, for example on preparing a nomination dossier for the World Heritage List.

We encourage professional users to register and login in order to view detailed information, propose a new case study or suggest changes to an existing one.


Astronomical heritage categories

Click on the different parts of this diagram to find out more about a certain category of astronomical heritage.

Sites and Landscapes Instruments and archives Knowledge and ideas Dark skies Cultural and natural


Regional and national heritage

We are developing a list of astronomical heritage resources at the regional or national level that are available on other internet sites. If you have items that you would like added to this list, please contact our This email address is being protected from spambots. You need JavaScript enabled to view it..


Dark skies

See our Dark Skies Information page for further information about International Dark Sky Reserves, Starlight Reserves, and other Dark Sky Places.

Full case studies

Full case studies, structured as sections of draft dossiers, aim to highlight issues that might arise if State Parties were to prepare nomination dossiers highlighting the astronomical values of the properties concerned. Examples:

Chankillo, Peru

Risco Caído and the sacred mountains of Gran Canaria, Spain

N.B. Both these properties have been inscribed on the World Heritage List since being published on the Portal.

IAU “Outstanding Astronomical Heritage” sites

Over 70 of the IAU’s outstanding astronomical heritage sites have now been published on the portal. These are sites considered outstanding in the history of astronomy but which are not necessarily suitable for inscription on the World Heritage List. The period from the European Renaissance to the middle of the 20th century was an extremely rich one for the history of astronomy and the IAU’s list so far focuses on sites of this type. Examples:

Uraniborg and Stellaeburgum, Sweden

La Plata Observatory, Argentina

Bosscha Observatory, Indonesia

Short case studies

Short case studies follow the format used in the ICOMOS–IAU Thematic Study on Astronomical Heritage. Examples:

Hortobágy Puszta, Hungary

Jantar Mantar at Jaipur, India

Sydney Observatory, Australia

Movable objects

We have recently introduced movable object case studies in order to document items such as artefacts and portable instruments in a more suitable format. Examples:

Nebra Sky Disc, Germany

Ishango Bone, Democratic Republic of the Congo

Places connected to the Sky

PC2S is our global community project, set up in 2019 as part of the IAU’s 100 Years Under one Sky celebrations.

The examples on the Portal illustrate some novel ways in which terrestrial locations can be connected to the sky, including:

Aiello del Friuli, village of sundials, Italy

Otford Solar System, UK, USA, Falkland Is., Australia, New Zealand

For more information follow this link!


Finding relevant information

You can locate case studies of interest both geographically and temporally using our astronomical heritage finder, or browse a complete list. You could also start from one of our Thematic Essays.

IAU - Astronomical Heritage in Danger

Since 2016, the IAU through its ‘Astronomical Heritage in Danger’ Working Group (part of Commission C4 - World Heritage and Astronomy) is compiling a list of sites with astronomical value relevant to humanity, which are currently at risk.

Many of these sites urgently need to be recognized as heritage sites by national governments, or even as potential UNESCO World Heritage Sites.

The primary purpose of this list is to influence governments, non-governmental organizations, international organizations, local authorities and decision makers to achieve the protection and care of these sites. Another purpose of this list is to make visible, based on the cases addressed, the limits and problems generated by the definitions currently in use of the concept of ‘heritage’ and its management by national and international institutions.

IAU members who are interested in proposing new sites for this list are invited to contact Alejandro López in the first instance. The list is not open to members of the public, but we invite anyone who is interested in submitting relevant places to add them instead as Places connected to the Sky, indicating that these are endangered sites.

Astronomical Heritage Finder - Legend

    Colours represent categories of astronomical heritage
  • Cultural - Tangible - Fixed
  • Cultural - Tangible - Movable
  • Cultural - Intangible
  • Cultural - Natural - Mixed
  • Natural - Dark Skies
  • Places connected to the Sky
    Shapes in relation to serial case studies
  • General description (main node)
  • Other nodes within the series

    Sizes represent different lists of Astronomical Heritage
  • AWHI, UNESCO, IAU lists
  • Places connected to the Sky
    RED represents Astronomical Heritage in danger
  • and   and   
The term `Heritage in danger´ is meant to inform the community that conditions prevail which threaten the very characteristics of that heritage (be it astronomical or otherwise), and to encourage corrective action. Armed conflict and war, earthquakes and other natural disasters, pollution, poaching, uncontrolled urbanization and unchecked tourist development pose major problems for heritage, including astronomical heritage. Dangers can be ‘ascertained’, referring to specific and proven imminent threats, or ‘potential’, when there are threats that could have negative effects on the (astronomical) heritage values. Details of the actual dangers for a specific property can be found in the respective entity's description.