Rotherhithe Tunnel is now closed to pedestrians. I found this out during the Open house weekend. My information that it was open was based on a walk by a friend on the occasion of the celebrations for the hundred years since it started. Maybe there is no notice on the south approach. Not sure about this. I did meet people during the weekend who were not convinced about the air quality but others can remember times when walking through was possible and frequent.

If you a wondering what this has to do with Exeter, the thing is that "wifi" now covers a wide range. the "open house" approach is in Exeter one weekend, somewhere else the next. see story for OhmyNews.

It also turned out that the Brunel tunnel was closed. This line will be part of the Overground, not the Underground and could be seen as an extension of the North London Line. Someone from London could explain this better, I can only repeat what I was told.

I still think a crossing of the Thames is useful at this point. Walking a bit further East than Tower Bridge is possible but Greenwich is a long way if you want to get back again. Apparently by 2010 it will be again possible to get a train from Rotherhithe to Wapping. So investigations continue about the rest of the loop.