Dressed in running gear we set off to find this road on the west side of Rome. Not hard to find and we felt ready to run along it towards the end where the dome of St Peter's appears to be smaller than at the beginning. We went on a quiet day so managed to run in the middle of the road. It was only a short run but fun as my eyes were focused on the dome to experience the illusion. At the end there was a little lay by so we could discuss what we had seen in full..throwing theories of perspective and perception..ah..magic..i love this experience..free and no queue needed.