On a crisp spring afternoon my 16-year-old son Ned and I left the Acropolis, strode through the Agora, and headed down the remains of the Panathenaic Way towards Piraeus and beyond in the footsteps of so many legendary Athenians. Every now and then modernity intervened: a railway track has long since sliced off a sliver of the Agora; a few hawkers lined the upper reaches of the ancient road. But as we neared the 2,400-year-old gate leading through the still imposing walls of classical Athens the subsequent centuries disappeared — as did other tourists — and we found ourselves in a tussocky park brimming with cats, wild flowers, and the marble remnants of a monumental past.