Carys Rees, who runs the This Girl Walks website and Instagram account and is also a member of the Central Beacons Mountain Rescue Team, said people seeing images on social media of the area must prepare before setting off.
Salisbury Cathedral's Sarum Lights was created by art company Luxmuralis and explores art, photography and societal changes across the centuries.The theme this year is time, with the event running every evening until Saturday.
Peter Walker, artistic director of Luxmuralis, said: "This large-scale installation is art on an epic scale, allowing visitors to experience how time has inspired and influenced scientists, historians and artists."He added the trip through history allows people to learn how time "determines all our lives".The "immersive" experience includes examples of early cave paintings and a walk through Einstein’s Theory of Relativity.
The projections will have text from HG Wells’ The Time Machine and show people the inner workings of clocks.An interactive installation called A Note to Myself will encourage visitors to write a message to themselves at other points in their lives.
The postcards will then become part of a cascade in the cathedral.
Sarum Lights is running from 17:30 GMT each evening until 9 November, and there will also be low sound screenings from between 17:30 and 18:30 on 5 and 6 November.The grey seal pups at Donna Nook are normally born white and shed their fur at about two to three weeks to expose a grey coat underneath.
However, about one in 400 grey seals reveal a velvety black coat instead and visitors in recent days have reported seeing at least two of these.As of 20 December, the Donna Nook warden reported that 1,647 pups had been born so far this season.
Street-food vendors have said they can "finally relax" after it was confirmed that their electricity supply will remain on.Taunton Town Council said it will invest in infrastructure to allow traders to measure and pay for their own electricity output on Fore Street.