A team of archaeologists has helped unlock 2000-year-old secrets of an ancient tower described as one of the wonders of European archaeology. Mousa Broch, located on the island of Mousa in Shetland (Scotland), is one of the finest examples of an Iron Age tower or broch. The impressive structure was used as a fortification when the islands were racked by warfare but was also mentioned in the sagas as an eloping lovers' hideout.
     Experts used the latest laser scanning techniques to record every detail of the historic monument and check whether it has shifted or deteriorated over the years. Laser scanning provides accurate and detailed information on the broch which can be of immense value in conservation and archaeological research. The technique, which will be used during a monitoring project, has already given experts a valuable insight into the ingenious engineering of the broch. Maintenance work will be carried out, as required, on the 44ft building which has been labelled the finest structure of its kind in the world.
     Alistair Carty, technical director of Archaeoptics, a 3D laser-scanning bureau operating in the archaeology and heritage sector, which carried out the project, said: "With the scans, you can spot how the broch has been constructed. The techniques used can be seen more clearly in the scans than in real life as the tower is covered in moss and lichen. The structure is just dry stone and there is no cement or other material binding the brickwork. If it moved, there would be a real danger of collapse. Dun Carloway, on the island of Lewis (Outer Hebrides, Scotland), is a case in point. In antiquity, half of the structure just fell apart. We obviously don't want that to happen in Mousa as it is the best example of a broch anywhere in the world. It is the only one which is complete right to the top. It even still has its internal stair well."
     It is thought that Mousa, which dates from around 100 BCE to 100 CE, marks the final stage in the development of the building of brochs. Some archaeologists once thought brochs were built by an influx of broch builders who had been displaced and pushed northward by the Roman invasion of Britain. However, this theory has been discounted and some experts now argue that the fortifications were the work of itinerant master craftsmen since so many have been built to almost the same design.
     A spokesman for Historic Scotland, which cares for the broch, said: "Mousa Broch is a monument of national importance and we want to make sure it is kept in the best possible condition. The survey will give us a near-perfect record of even the tiniest details of the broch. It will also tell us whether any movement has taken place in the last couple of years and help us decide on the nature of future works."

Source: The Herald (4 January 2005)