Earlier this month, I met up with concreteJungle and popped in to take some photos of this warren of wonderful tunnels below North London.
Beginning in Knightsbridge we took a long walk up the Ranelagh CSO tunnel where tree roots entered via side pipes and collected all manner of filthy debris. Some way on a fantastic spiral staircase led up to the surface.
Finally we reached the destination that we were waiting to see, the CSO chamber with the Middle Level Sewer running through it. The chamber is most impressive due to the beautiful curved brickwork everywhere to ensure minimum resistance to the flow of water.
Once we had finished taking photos here, we began the walk back downstream and then dropped down in to The Egg where we passed underneath the Ranelagh Sewer aka River Westbourne and headed east until we arrived at the CSO chamber with the River Tyburn aka the King's Scholars' Pond Sewer (KSPS).
Thanks to Jondoe and Guerrillaexplorer066 for clarification on the layout and specifications of the CSO Chamber and the Ranelagh Sewer. :)