In the morning the Lord Mayor's Procession goes from Mansion House to the Royal Courts via St Pauls. In the early afternoon it comes back again via the Embankment and Victoria Street. The procession is much longer than the route, so for most of that time the streets are completely full.
The best places to go depend on how much you like a crowd and what else you would like to do on the day. Here are some suggestions:
For the full Lord Mayor's Show experience
Watch the outward procession from 11 to 12 in the area between Bank and St Pauls
The outward journey squeezes down relatively narrow City streets past very lively crowds. It is broadcast live by the BBC from the Bank / Mansion House area and passes the grandstands at St Pauls before heading down Ludgate Hill to Fleet Street. All of those places are busy and crowded and for the full-strength Show that's definitely the place to be.
For the quiet, spacious version
Watch the return procession between 1.15 and 2.30 in the Embankment area
When the procession heads back towards Mansion House things will get busy again, but the stretch from Temple to Blackfriars is much quieter and the roads and pavements are wider. It's easy to get around and there will be room for wheelchairs, luggage, folding chairs and families.
To see the Flotilla and the Procession
Head for London Bridge at about 9.15 and then walk up to Bank
Tower Bridge will open to salute the flotilla at 9.25 then there are a few coffee shops on the way up to Bank, where you should arrive at about the right time to secure a good spot.
To go into the West End afterwards
Watch the outward procession on Fleet Street between 11.30 and 12.30
From here it's an easy walk across to Kingsway, Covent Garden and Leicester Square. Watch out for congestion on the south side of Fleet Street; the whole procession is having lunch in the side streets around Temple, and it can take a long time to get through.