Rye Lane, Peckham
Major shopping street in Peckham, lined with fishmongers, ironmongers, and greengrocers. It's also known as the A2215, for those who are interested in such things.
It's easy to get to because it also houses Peckham Rye Station.
OS X co-ord: 534285 OS Y co-ord: 176265 (Latitude: 51.468910 Longitude: -0.066460)