One of the things that fascinates me about my city is its Roman heritage. There are Roman ruins everywhere, and every child studies them during their school years. The Roman aqueduct is my favourite and a must-visit for pupils right across Catalonia. When we moved to Barcelona when I was nine, we came to Tarragona for a school trip. When I saw the aqueduct, I told my friends: ‘I’ve already been here many times! It’s from the 1st century AD!’

During a visit to the city’s archaeological museum, I was impressed by a ‘rearrangement puzzle’. It involves fitting geometric pieces together and is considered to be one of the precursors to jigsaw puzzles. This was a Roman version of what’s been called the oldest maths puzzle in the world - a 14-piece stomachion, said to be invented by the Greek mathematician Archimedes. The Romans popularised it and simplified. it. These days it’s the 7-piece Chinese tangram that’s popular - but I love the thought that I was puzzling over more or less the same thing as the Romans. You can arrange the pieces into a perfect square (see p 26 for the solution), or have a go at some of these shapes.

You can find many more tangram puzzles online, for example at brainzilla.com