The major lunar event that occurs every 18.6 years to be marked at ancient Calanais Standing Stones

A lunar standstill is due to be observed at the Neolithic wonder on June 12, 2025.

So important is the lunar standstill to Calanais and its story that the entire complex stone monument was re-orientated around 2,500 BC to align it to the event.

For 2025, discussions are ongoing to decide how the lunar standstill can be marked. A creative residency to reflect on the celestial event has been launched and a livestream of the moon’s movements across the Calanais landscape is being considered with the help of English Heritage, which runs similar broadcasts at Stonehenge.

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However, Urras nan Tursachan, the trust that runs the Calanais Visitor Centre, has warned it will not be possible to host large numbers at the standing stones given the fragile nature of the site.

A statement on the website said: “The monument at Calanais was constructed as a sacred site, not as a destination for mass tourism, and it is vulnerable to damage from excessive footfall from visitors.

“It will not be possible for large numbers of people to witness the phenomenon at the monument itself and there is only very limited parking space, so in-person visits to the site at these times are not encouraged.”

The lunar standstill occurs when the moon’s rising and setting positions are at their southernmost point and furthest apart.

When viewed from the northern end of the Avenue at Calanais, the full moon’s path from rising to setting means that it appears to skim across the hills to the south of the complex known as “Cailleach na Mointeach” or “The Old Woman of the Moors”, which take their name given their silhouette is shaped like a woman lying on her back.

After disappearing, the moon reappears and then shines into the centre of the circle at the southern end of the Calanais monument as it sets.

In the past, people processed southwards along the Avenue to celebrate this awe-inspiring occurrence, it is believed.

Before Calanais was realigned to optimise its position during the lunar standstill, Calanais was a free-standing circle with a tall central stone, according to the trust. It was constructed, it is believed, to principally mark the winter solstice.

Last year, the lunar standstill was close enough to its 2025 position for it to be marked at Calanais. The trust then worked with English Heritage on a livestream, with hopes to repeat the film this year on June 12 between 1.57am and 3.54am. The lunar standstill will be visible on other key dates between July and September.

As part of the celebrations, a creative residency has been opened up by Urras nan Tursachan to create original works or research inspired by the lunar standstill.

“It is a unique opportunity to spend time at this iconic monument during a significant astronomical event,” a statement said.

Projects should explore the astronomical, archaeological, cultural, or artistic significance of the Calanais Standing Stones during the celestial event.

It is open to specialists and creatives from any field - art to archaeology, astrophysics to geophysics, astronomy to digital media, storytelling to any other artistic or research discipline Applications should be made to [email protected] by 5pm on Monday, March 17.