Following the Aqueduct from the Spanish Steps to the Trevi Cistern

Twelve people at most, and a walk with an actual argument rather than a list of stops: it follows one aqueduct from end to end. It starts at the Spanish Steps, where the guide deals with the question everyone asks and nobody answers, which is why a staircase in Rome is called Spanish when nothing about it is. The Barcaccia fountain at the bottom is the first stop on the water route, because it still runs on an aqueduct opened in 19 BC. From there the walk follows that aqueduct through the streets. It is underground for most of its length, but it surfaces: a stretch of arches between two modern buildings, a door that goes nowhere obvious, and, under a department store on Via del Tritone, the exposed ruins of the only ancient Roman aqueduct still working today. You go down and look at it. The route ends where the aqueduct does, at the Trevi Fountain, and then keeps going: round the corner and down into Vicus Caprarius, the cistern and residential block the Romans built to hold that same water two thousand years ago. What you take away is how modern Rome was built on top of the ancient one rather than beside it.