Rome, St Peter's basilica

View from the red open top hop-on-hop-off bus. 
This seemed the best way to see the centre of Rome, and we certainly knew the route quite well by the end of 3 days. Beautiful clear sky everyday. Quite chilly on the top of the bus (mid December after all) but it warmed up mid-day. Rome is a 'walking city' but this saved these oldies too much walking. And the constant change of view, and seeing the layers of history at each turn took our breath away.