When Julian Cope, the musician and antiquary, met Margaret Curtis on the Isle of Lewis in the 1990s, he was impressed. Curtis, who has died aged 80, was a “living legend” and a “psychic queen”, said Cope, who filled him with “a real sense of awe”. He devoted a chapter in his bestselling 1998 book The Modern Antiquarian to her and to Calanais, one of the most extraordinary ancient monuments in Europe.

Near the Atlantic coast in the remote Outer Hebrides, Calanais (pronounced as in the anglicised spelling, Callanish) is a stone circle at the centre of five rows dating from around 3000BC. The tallest of nearly 50 megaliths is over five metres high, and all are made of a distinctive streaked gneiss that glows against stormy skies. Curtis did much to further understanding of this and other overlooked sites on Lewis, becoming the island’s unofficial archaeologist and sharing her enthusiasms with an appreciative visiting public.

She found many more stones under the peat as she walked the moorland, probing with a metal bar. One, at Calanais itself, was re-erected in 1982, and she spotted the broken tip of another in a wall.

Archaeologists sometimes followed up her suggestions. Patrick Ashmore, who led excavations at Calanais for what is now Historic Scotland in the 1980s, praised the fieldwork and record-keeping of Curtis and each of her two husbands. On one occasion, quartz pieces she found when a road near her house was straightened led to the discovery of a bronze age burial cairn.

Archaeologists did not support all her ideas, but embraced her notion of a great sacred landscape. At the centre of this, she argued, was a dramatic moonset that occurs every 18 years and seven months.

At that moment (next up in 2025) the midsummer full moon rises behind a hill – shaped like a sleeping woman, she said, representing an ancient goddess – skims the horizon and sets, before briefly reappearing behind the Calanais circle. “She had a keen sense of the theatrical,” says Alison Sheridan, a former principal curator at National Museums Scotland.

Margaret was the adopted daughter of Doris (nee Cattermole) and Charles Woolford, who lived in Edgbaston, Birmingham. Charles was a railway engineer, and Doris a teacher before her marriage. Late in life Margaret found and visited her birth mother, who lived near Edinburgh.

After school in Edgbaston, Margaret qualified as a teacher at Maria Grey College, Twickenham. She met Gerald Ponting, then training to teach in Southampton, when they were students at a conservation camp in Anglesey. They married in 1967 and took up jobs in Suffolk, where they lived in Kesgrave, near Ipswich, Margaret teaching at a primary school. They were both interested in local history, and after they had moved to Scotland they self-published a book about Kesgrave.

They spent their summer holidays travelling, first with a tent and later a Bedford campervan, at locations ranging from Iceland to Turkey, and often on the west coast of Britain. In 1973 Gerald successfully applied for a job in Stornoway, the capital of Lewis and Harris, teaching biology and science at a secondary school, and they moved there the following year, Margaret driving the old van from Suffolk with their two young children.

In Lewis she became a peripatetic primary school music teacher in villages strung out along a 35-mile road. She was keen to escape what she saw as the urbanisation of the English countryside, and the family embraced a crofting lifestyle with a large vegetable garden, chickens, goats and sheep, making hay and cutting peat.

They had previously taken a casual interest in archaeology – the year before the move Margaret had volunteered on an excavation in Suffolk – and they had seen Calanais on summer holidays. However, their house was close to the megaliths, and as a birthday present for Margaret, Gerald found a book about standing stones. Antiquarian curiosity soon became all-consuming.

The book was Megalithic Sites in Britain (1967), by Alexander Thom, a professor of engineering science at Oxford University. Though published by a university press, it acquired a cult following, introducing the world to a “megalithic yard” and the idea that stone circles were laid out with extreme precision, sometimes aligned on features of the night sky. Calanais and its surrounding sites were said to display “the most important group of alignments in Britain”. Here, wrote Thom, there is no complete survey. The Pontings got in touch.

Margaret corresponded regularly with Thom, a man she found more helpful than many professional archaeologists, and he introduced them to Ronald Curtis, an Edinburgh-based chartered civil engineer who had started his own surveys at Calanais in 1972. Within a year Margaret had found previously unidentified megaliths, and the Pontings soon joined Ron Curtis in surveying many of them.

Their work was highlighted in 1978 when Margaret and Gerald were finalists in the BBC Chronicle award for local amateur archaeologists. They were not winners, but at the ceremony were presented with a cheque and champagne by Prince Charles as a special award for initiative.

They self-published a succession of guides to Calanais and other stone circles, selling them from the garage next to their house, where Margaret accumulated her collection of artefacts and entertained visitors from around the world drawn by promises of visionary tours and eccentric, friendly company.

Gerald left Scotland in 1984 after they had separated, and Margaret continued to work with Curtis. They married in 1989, co-authoring many technical reports of surveys and discoveries, which included a complete stone circle which Margaret first spotted from a bus. Their experiments in moving and erecting stones attracted the attention of the mason and writer Rob Roy, who gave Margaret another book chapter, in his Stone Circles: A Modern Builder’s Guide (1999).

In September last year, Peter Vallance, a storyteller at the Findhorn Foundation, recorded Margaret talking by the Calanais stones. “It’s like doing a jigsaw,” she said, “every little bit gives you another insight into what was going on. And I think I’ve pretty well got to the end of all the insights.”

Ron died in 2008. Margaret is survived by her son, Ben, and daughter, Becky, four grandchildren, Eloise, Sasha, Tabitha and Calum, and two great-grandsons.

• Margaret Curtis, teacher, archaeologist and megalith enthusiast, born 7 June 1941; died 26 March 2022