Julia Farley, Curator, European Iron Age collection, British Museum

As curator of the Celts exhibition, I get to spend a lot of time showing people wonderful Iron Age treasures. Some of my favourites are the big metal neck rings called torcs that were worn across much of Europe (and beyond) around 2000 years ago. One of the things I get asked most often is, ‘But how did you put them on?!’ It’s a very good question, seeing as they often look like solid metal rings with nowhere near enough space to squeeze your neck through.

Many British torcs are a bit like this one:

The Snettisham Great Torc. Found in Snettisham, UK. Electrum, 150 BC–50 BC. Diam. 19.9 cm. British Museum 1951,0402.2. (Photo: (c) The Trustees of the British Museum)

Although this is one of the most famous examples, the form is typical: open at the front, with a flexible…