When I still lived abroad, I once visited my brother in Rome with two Irish friends, who were astonished by the fact the city only had two underground lines (it’s three today). “Well, every time they begin digging, something archaeologically valuable comes out of the ground!” - my brother would cheerfully explain.

While that may not be the sole reason behind our capital’s paucity of underground transportation, it certainly points at a well established reality of Rome and, in truth, of many areas of Italy, country where millennial history means we, quite literally, live on top of the cities of a bunch of centuries ago.