"I gave notice on the Sunday following, I would preach in a place at the end of the town, where four ways met. The town and villages round were soon alarmed, and at the time appointed I believe there were three or four thousand people. I got upon a wall about seven feet high and began with prayer. Surely I preached the sermon with the power of the Holy Spirit sent down from heaven. Twelve, if not fourteen were then convinced of sin... Within a few weeks, fifty were joined together in society."
'The Lives of Early Methodist Preachers', by Thomas Jackson, Volume 1, page 303/4.
This is possibly the place described.