Ian and Phil take Wales's 'worst road' to Maentwrog to reach an old toll house - exactly 220 miles from London.
Click here to listen...

Ian and Phil try to spot the hidden milestone on the Harlech to Barmouth coast road.
Click here to listen...

Down to Pen Llŷn, and Bleddyn Jones from the county council explains why maintaining these historic milestones is so important to our heritage.
Click here to listen...

Ian leads Phil up a very steep hill - did coaches really go up there? There's certainly a milestone.
Click here to listen...

They reach the original north to south Wales road, built by the Romans long before the A470.
Click here to listen...

Ian and Phil's journey comes to an end on the original London to Holyhead route, where the milestones still stand - though perhaps in need of some TLC.
Click here to listen...