Piazza Navona

Piazza Navona is oval because it is built on the running track of Domitian's stadium: the ochre and cream facades stand exactly where the tiers of seats once did, which is why the square has a shape no other Roman piazza has. Three fountains run down its long axis, with Bernini's Four Rivers — an obelisk carried on a hollowed rock, four river gods sprawled around it — in the middle.

The piazza is long and narrow, so it photographs best along its length rather than across it. Stand at the southern end near the Moor fountain and the whole axis leads the eye up to the obelisk and Sant'Agnese in Agone behind it. Early light rakes across the western facades and leaves the eastern side in shade — a hard line that is worth composing for rather than fighting.

Before nine the square belongs to people walking to work and to the cafés setting out chairs. Later it fills with portrait artists, tables and queues, and there is no angle that hides them. The narrow streets to the west, around Via della Pace and Via dei Coronari, are two minutes away and carry the rest of the session with ivy, arches and empty cobbles.