We have had 3 consecutive days of rain, and I was worried that the trenches would be giant mud puddles. They are not in bad shape, though. In A we are continuing A2 - it contains noticeably less material than A1. Have come down upon some wall fall, which we are slowly removing. Still black soil with no sign of the tan layer seen at the bottom of B2. In B, we are continuing B2. The tan dirt contains discrete charcoal patches - ATS thinks they look like postholes - and it is still limited to the SW corner. We came up a curved wall in the SE part of B - it is Wall B3. Today I also noticed that the stones in the south baulk on the west side are actually a wall - Wall B4. The stones in this wall are covered in black soil and soot - clear evidence of burning, but we are not at the bottom of the wall yet. Took a carbon sample.