Despite being 1600 years old, this seven-metre high pillar has never rusted. It was made during the reign of Chandragupta II (reigned about 375–415) – we know this because the lack of rusting has resulted in the inscription remaining clear and readable …

We’ve all seen a footprint in wet concrete, set into the pavement for posterity. The Roman who made this clay tile probably didn’t expect a dog to run over it as it was drying …