I think North Dulwich is just the name of the station, but the area around it has unofficially taken on that name. It's not an unusual phenomenon by any means, London is full of examples. The station is tecnhincally in SE21 (Dulwich), but it's right on the border of Herne Hill, East Dulwich, and Camberwell. So if someone says they live in North Dulwich, I guess it could really be in any of those areas. The rounds around Sydenham Hill are quite expensive enough without any silly name changes. Frankito - you're right, I walked through DV half an hour ago and it was absolutely dead. ED is definitely preferable.