The secret royal 'pyramids' of Scotland

When Queen Victoria first visited Balmoral Castle in rural Aberdeenshire on 8 September 1848, six years after her first visit to Scotland, she took time out to appreciate the woodlands, gardens and rippling mountains.

Perhaps she deeply breathed in the Caledonian pine air. Perhaps a deer stood motionless, caught in her gaze. Certainly, she saw a different future for herself and her husband, Prince Albert, on Deeside in the Highlands. "All seemed to breathe freedom and peace, and to make one forget the world and its sad turmoils," she recorded in her diary. Soon after, the baronial estate became a mainstay for the rest of her life – and it remains a sanctuary for the British Royal Family to this day.

There are many stories hidden at Balmoral Castle, but perhaps none so intriguing as that of the estate's secret "pyramids", or memorial cairns. There are 11 of these, strewn almost negligently around the near-50,000-acre estate. The largest is a stone monolith more in keeping with the design of the great dynastic structures of Ancient Egypt than anything Scottish, while the smaller ones are scattered like clues to a greater mystery. And seeking them out – on a hunt akin to an Indiana Jones-type treasure hunt – is a little bit of everyday magic hidden among the Scots pine, firs and hemlocks.

Like many visitors to the Royal Deeside, I'd been to the country's best-known estate before. Located in the eastern Cairngorm mountains, the turreted 167-room castle, ballroom, mews courtyard, sunken garden and thistle-shaped maze are a bonanza for visitors, especially between April and early August when the full grandeur of the castle is open to ticketed visitors. There are around 80 residential properties on the wider estate, too, plus commercial forestry plantations, a hydroelectric dam, facilities for deer stalking and grouse shooting and a golf course.