Starting in the west at present day Blackfriars Bridge walk north only about 200 yards to "Ludgate" (now Ludgate circus).Continue north up Farringdon road and stop under Holborn Viaduct which used to be the junction with Newgate Street.
For those who know London this area would obviously have made a good port with immediate access to high dry ground.
(Note the present day embankment did not exist.) The only building of note in the old Roman area which was used by the Saxons was the site of St Paul's for a church of that name.
London Wall was the northern boundary and over a bridge (on the site of present day London Bridge) to present day Southwark described the city limits in the south .
Hence the area north of the Thames was approximately ½ mile north south and just over a mile east west.
Turn right up Snow Hill to Newgate St and at St Bartholomew's hospital you are now at the position of Aldersgate Make your way to London Wall (Street) and walk east, close to Moorgate tube station then Bishopsgate (street) towards Houdsditch (street) and cross Aldgate High Street and south towards the Tower of London down The Minories (street). Many of the Roman London houses and the city wall were built of "Ragstone" which was quarried about 30 miles to the east of London at Maidstone in Kent.