It was 9am in Rome, and the Colosseum cast great shadows across well-formed queues of tourists edging closer to the almost 2,000-year-old entrance. I’d braved this queue many years before on my first visit to the Italian capital, but this time I’d arrived in Rome the night before with the intention of escaping the city almost immediately.
I wasn’t here to see the Forum, the Pantheon or the Baths of Caracalla either; I was here to see a lesser-known work of Roman engineering arguably more vital to Roman history than amphitheatres and hippodromes. I pushed against the tide of tourists walking towards the Colosseum and instead made my way to a bicycle rental shop on a nearby sidestreet.
