The stratigraphic relationships are fairly clear relating to this feature, but unfortunately its function remains a mystery. Phasing: 17217 is cut into 17215 and 17219, suggesting that these SUs once formed a surface and that this surface predates wall 19002 because 17217 is cut by 19002. However, in the north of the trench, 17216 seems to have accumulated on a surface below the upper limit of 17215 since it dives below 17215 towards the northern baulk (note that 17215 was identified but only excavated in a small section in the east). Below 17216, 17220 fills a clear square cut (cut 17225) which emerged ~7cm below upper limits of 17215 (we dug an artificial sondage to find the cardinal extents of the forge deposit). The most likely phasing seems to be that 17225 was cut into a surface below the upper limits of 17215, 17220 filled cut 17225, 17216 was deposited on top of 17220, and finally 17215 accumulated around that. 17217 is cut into this later surface of 17215 and wall 19002 cuts 17217. This suggests the following phasing: 1) metalworking activity occurred in 17225/17220/17216; 2) trench 17217=17222 is dug; 3) the opus reticulatum structure is built.

Possible drain? 17217 slopes upwards towards the SE and so may have originally been intended to have some drainage function. If so, it was either a very crude drain (having no drainage infrastructure at the bottom), abandoned prior to being finished, or the drainage infrastructure was removed prior to it being backfilled, perhaps for reuse elsewhere. The fact that 17217 is on a similar alignment to the drains in area 20,000 and slopes downwards towards the creek suggests drainage function. If it was a drain it is probably associated with some activity further to the SE since it continues into the southern baulk. It runs close to the metal working area (17216/17220/17225), but seems to postdate this feature since 17217 is cut into 17215.

17217 has the correct proportions to be a foundation trench for a wall and is very regular in shape. It is possible that this cut was an earlier attempt at wall construction that was abandoned prior to a new alignment being used for the structure associated with wall 19002.