Grantham Canal - bits of rusty metal and other interesting stuff.

Sometime around 2000/01/02 when I was a student living in Loughborough, I visited a canal nearby that was in a derelict state. My memory of the visit is hazy but I recall walking along the dry bed of the canal in a fairly rural area and walking into an empty lock chamber. Although derelict the chamber was clear of any vegetation from what I remember. Both the floor and walls were brick built. Possibly the most distinguishing feature was a step on the chamber floor where there had been some subsidence. I don't recall any fencing around the chamber at all!
I've ruled out the Ashby canal and the Charnwood Forest Canals, as these don't have any dry locks. Back in the day I've seen photos of the lock chamber I stood in, also showing the step in the floor from subsidence, but I can't find anything now.
Can any knowledgeable folk here can confirm where I was? Seems like the Grantham is the only likely candidate.