Why Scottish Archaeologists Are Building a Replica of an Iron Age Stone Tower

By building a new broch, the project aims to better understand how and why the original structures were constructed

Mousa Broch
A tourist visits Mousa Broch, the tallest known Iron Age broch and one of Europe's best-preserved prehistoric buildings Photo by Arterra / Universal Images Group via Getty Images

In 2013, archaeologist Kenneth McElroy and builder Iain Maclean co-founded the Caithness Broch Project in hopes of reviving an Iron Age architectural style unique to Scotland.

In the years since, the charity, which derives its name from the circular stone towers at the heart of its mission, has prioritized the preservation of existing brochs across the region. But as Libby Brooks reports for the Guardian, the organization was just weeks away from launching its “flagship experiment”—using authentic Iron Age building techniques to construct a modern replica of the formidable structure—when Great Britain went on lockdown due to COVID-19. For now, at least, it appears the rebirth of Scotland’s brochs will have to wait.

Brochs are unique to northern and western Scotland, with the majority found in Caithness county, according to the Scotsman. A replica tower could help archaeologists understand how Iron Age masons created the structures without using mortar to hold the stones together.

“There are so many unanswerable questions in archaeology, and in the past,” McElroy tells the Guardian. “But this should go some way to revealing more about our [Iron Age] ancestors.”

Brochs, which are alternatively classified as defensive forts, dwellings and status symbols, are impressive not only for their height, but for their double-walled construction. The round buildings’ layered walls have a gap in between them, making the fortifications about ten feet thick. These gaps, called galleries, may have afforded the towers’ inhabitants protection from rain and snow, preventing the elements from permeating the brochs’ inner walls, writes McElroy for Historic Environment Scotland. Steps running between the walls potentially led to living spaces on upper wooden platforms, per Historic U.K.’s Ben Johnson.

Between 500 and 600 broch ruins dot the Scottish landscape today, with the highest concentrations in Caithness and on the Orkney and Shetland islands, according to Historic Environment Scotland. Perhaps the most pressing threat to these ancient structures’ survival is climate change: As Reuters’ George Sargent reported last October, rising sea levels, erosion and extreme weather are among the many forces placing Scotland’s brochs at risk.

Referencing the South Howe Broch on the island of Rousay, Julie Gibson, an archaeologist at the University of the Highlands and Islands, told Reuters, “On this stretch of the coastline, all the settlement archaeology is within 100 meters of the coast edge. And so ... the sea takes this heritage of ours away.”

Interior view of Mousa Broch
Interior view of Mousa Broch Photo by David Tipling / Universal Images Group via Getty Images

Brochs continue to yield significant Iron Age artifacts today. Pottery fragments discovered near some of the ancient towers show that their residents imported wine and olives from the Mediterranean. In 2018, archaeologists found a 2,000-year-old wooden bowl and a strand of hair at the Cairns Broch in Orkney. And last November, archaeologists unearthed a human jawbone and the remains of two newborn lambs inside of a hollow whale vertebra.

Before COVID-19 shuttered operations, the Caithness Broch Project was nearly finished with its preservation work at the Ousdale Broch. The stone structure had fallen into disrepair over the centuries, so the team removed an invading rowan tree and cleaned up its collapsed walls. The broch’s extant features include a staircase against its inner wall; a guard cell; and a restored display area, called an aumbry, inside the lower chamber.

“This aumbry may have held treasured possessions; perhaps the families who once lived here displayed things very dear to them, or objects which could impress visitors,” writes McElroy in a blog post.

The archaeologist clarifies that the Caithness Broch Project’s intention at Ousdale was not to rebuild the broch, but to conserve it as it was found. The last step in preservation is to lay down a gravel floor, making the structure safe for visitors to explore.

After work at Ousdale is finished, the team will move forward with the replica broch project. This won’t be the first time members build an ancient stone tower with modern materials: In 2017, the organization worked with creative collective Brick to the Past to create a historically accurate, albeit scaled-down, broch out of Legos.

The Caithness Broch Project is still searching for a suitable location to build its new, full-scale broch. In addition to driving tourism and contributing to archaeologists’ understanding of the Iron Age structures, the project will act as an opportunity to practice traditional drystone construction techniques.

“Experimental archaeology is a more practical and innovative way of dealing with the difficult questions posed by these enigmatic constructions,” McElroy tells the Guardian. “In turn, this helps us to better understand peoples of Scotland, and what drove them to build such impressive constructions.”

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