Report covering both the field investigation of Seething Lane, and the watching brief undertaken on Crouch Hill 55 from June 09 - August 10 in relation to the Thames Water Mains replacement works programme. Includes detailed discussion of history of Seething Lane site (use of documentary, cartographic and pictorial sources) and discussion of field evaluation itself (discussion of trenches, finds and interpretations - with relevant plans, sections and photographs). Interim report includes a brief discussion of each trench monitored.