The Lough Gur Dark Sky Project


The Dark Sky project is a significant undertaking by the Lough Gur group to secure International Dark Sky Association status for Lough Gur. But more important than being able to claim international status is the import task of preserving, not just the physical sites around Lough Gur, but the night skies overhead which has been available to man, woman and child at Lough Gur for over 6000 years.

As such we have embarked on a scientific measurement of how dark our skies are throughout the year and making that information readily available to you our visitors to Lough Gur.

Lough Gur is home to an array of species from insects, to small mammals, fish, birds and bats. We are acutely aware that changes to our ecosystem will have a significant impact on our broad ecosystems. Equally lighting changes will have a direct impact on the insect population and in turn the fish and bats and so forth. As the grounds are managed by Limerick council we are also fortunate to have access and support of our park ranger.

Dark Skies are our Connection with a 6000 Years of History

While no-one fully understands the purpose of the great stone circle, we can only image how our 6000-year-old ancestors pondered on the night sky and how it impacted their belief systems and annual cycles of life. A culture which we believe had at it heart the seasonal movements of sun, moon and stars. We want future generations to be in a position to look up and appreciate those same skies, it’s one of our few links to the past.

Spirit of Place

Visitors to Lough Gur are not only invited to enjoy its mystical presence but are invited to immerse themselves into human spirit and wellness. As part of our annual calendar, we run a “Spirit of Place” event promoting human wellness.

Increasingly critical to our own well-being is understanding the impact of blue light & light pollution on the human body. There is scientific evidence that suggests that for our own wellbeing, humans can greatly benefit from managed lighting and dark spaces.

A Historical Treasure we are passing to the future

Dark Sky certification for Lough Gur is not a point in time exercise. Our Dark Skies have been observed by generations of people over 6000 years, We want to play our part to ensure the skies remain as an inspiration for others over the coming 6000 years. Lough Gur is fortunate to have the backing of Limerick Council and local community in building sustainable model for dark sky preservation We invite you to explore our Dark Sky image above, clicking through to the various aspects of our Dark Sky project and related areas. Lough Gur Science Group.

Dark Sky & Science Education

What can I learn?

The “Dark Sky Project” segment of our website is an educational tool which we are happy to make freely available to everyone, which can be accessed directly by students or as an inspirational teaching guide for the classroom. Our project extends well beyond the stars to numerous disciplines including:


Understanding Lunar & Solar orbits.

Learning about the seasons

Data Analytics

Ecology and Impact of Light on Flora & Fauna


Human Wellbeing

Using our Data & Ideas for Students

We welcome you to use our interactive online analytics tools from Tableau Public. Or indeed download our data for your own analysis with your tools of choice. Here are some ideas for class room projects when using our data:

Finding the pattern & impact of Lunar Orbits

Look for the impact of the Earth’s spins and orbit around the sun.

Comparing seasonal numbers by day, month or quarter.

Select a single day and see if you can determine what is happening that day.

Understanding the impact of city lighting, the moon, clouds and sun on our light readings.

How does our data support what we know about our planet?

We encourage you to explore, play and find new answers in our data.

Dark Sky & The

Stone Circle

Ancients Look to the Skies

As our ancestors looked to the sky, it presumably took several generations to identify and map the patterns which existed. We can only speculate that these patterns acted as seasonal indicators to Bronze Age families. 6,000 years ago, in the absence of city lights, our dark sky at Lough Gur would have been even more impressive than it is today, with artefacts like the Milkyway clearly visible.

2017 Archaeoastronomical Report by Dr Frank Prendergast FSCSI FRICS

In July of 2017, the management of Lough Gur commissioned Dr. Prendergast to carry out a review of the Great Stone Cricle (Circle B) at Grange, In the report Dr. Prendergast explores various aspect of how the stone circle would have been of immense social and astronomical significance to the inhabitants of Lough Gur at that time. The following is an extract from that report.

Throughout prehistory, humans would have perpetually gazed at and interpreted the sky – by day and by night – and been acutely aware of their perceived universe. There is little doubt that such practices in the past were an integral part of their cosmology. Mainstream archaeology, with archaeoastronomy, now factors these broader perspectives into understanding ancient societies in terms of everyday life and belief systems in the prehistoric past. Justifiably, an appreciation of the symbolic sky as the natural extension of landscape studies is essential, warranted and rapidly growing in importance. Circle (B) is the logical and appropriate place in which to inspire visitors of all ages by connecting to our distant ancestors. Recognisable astronomical alignments cannot be identified at the site but, nonetheless, it is justifiable to presume that its builders readily understood the passage of time and the seasons and how these were linked to the apparent movement of celestial bodies, planting and harvesting cycles. Additionally, the rituals of death and burial would have been synonymous with the darker months of the year and perhaps marked there. Being located in Circle (B) at the shortest days of the year when the sun’s passage was lowest and shortest would have arguably carried added symbolism as well as deep levels of fear and awe. Modern humans have largely disconnected from their natural world and now exist in a very different environment.

mpact of the Moon on Dark Skies

Even through Lough Gur is fortunate to be located in an area with such wonderful dark skies, the data from our light meter had periodic drops in darkness. Regardless of the weather, seasonal or any other influences these periodic spikes in brightness are attributed to lunar phases – the full moon. On focusing on any given night you do not seem a smooth transition of brightness to dark. On nights of a full moon, cloud cover will darken the skies marginally. Interestingly on a dark night, the overhead cloud has the impact of bouncing ground lighting back to earth and our light meter.

Lunar Cycles

The Moon takes 29.53 days to go from new Moon to new Moon. The Earth travels 72.4 million kilometers around the Sun during the time it takes the moon to orbit the earth. This Nasa Goddard 4K visualization shows the Moon’s phase and libration at hourly intervals throughout 2016, as viewed from the northern hemisphere. Each frame represents one hour. In addition, this visualization shows the Moon’s orbit position, sub-Earth and subsolar points, distance from the Earth at true scale, and labels of craters near the terminator.

5 Reasons to Stargaze at Lough Gur

Proximity to Limerick & Surrounding Towns

Ever got in your car to drive for hours to reach a dark sky site, such as the Burren, to discover when you get there the weather has turned and rain/cloud-cover has put an end to your observations? At only 21km from Limerick city, you can glance to the sky and be at Lough Gur in 30 minutes. And if the weather does turn, you can be back in the comfort of your home 30 minutes later.

Still Air Over the Lake

The water volume of the lake acts as a natural temperature control for surrounding air. As such the air is still and your observations are less likely to suffer from the effect of air movement or changing air temperature. The lakefront provides an ideal location to observe the southerly and westerly skies.

Ample Parking & Safe Environment

As a managed park Lough Gur offers ample parking. Ideal for groups or club meetings. Keep an eye on the Shannonside Astronomy Club who use Lough Gur are an observation location.

A Protected Environment

Lough Gur is protected in many ways. At a government level, the area is a restricted zone for planning permission, guaranteeing we protect our dark sky from needless light pollution. The unique of Lough Gur, while at an elevated altitude, it is further protected from light pollution by surrounding hills which act as a natural barrier to city & local town light.

SQM Readings in Excess of 21

Our Sky Quality Meter measures our sky in excess of 21, with a maximum reading of 22.29 during the past year. The data supports the anecdotal evidence from locals that the skies over Lough Gur are truly unique.


Not many of us will get the opportunity to observe the Milky Way in its full glory. But when the weather conditions are right at Lough Gur you can do just that. The following photo was taken by local photographer Brian Lavelle and featured in the 2017 Lough Gur Calendar. On the night in question, the lake was so still that the stars were reflected in the water. The lake front is open to the public 24x7x365. With accessible parking within walking distance, come along, setup your equipment to capture the wonders of the night sky. When looking at such an amazing sight, it is easy to see what may have inspired our ancestors to build the Great Stone circle.