An archaeological investigation by means of 122 trial trenches was carried out by Oxford Archaeology in November 2013 in advance of wildlife habitat restoration.

A definite area of medieval activity in Site 1 which could possibly be a medieval Saltern was uncovered as well as post-medieval/modern sheepfolds.

A Tudor brick surface, three undated postholes and a ubiquitous presence of palaeochannels were also present.

A relatively small number of various finds, mostly medieval and post-medieval/modern in date were also recovered from the site.

The site report summarises the archaeology present as follows:
"Archaeological remains within the top 1m of the sediment sequence were very sparsely
distributed in general. The trenching has successfully characterised various potentially
significant archaeological features identified by the previous surveys. Most of the
geophysical anomalies investigated appear to relate to infilled former channels, which were
recognised in 50 of the trenches.
The most significant archaeology comprised a series of medieval mound deposits and
dumps of domestic refuse, interpreted as a possible salt-making site, subsequently re-used
as a sheep-fold/ refuge mound (Site 1), which is located between Salt Fleet and Hope Fleet,
near the southern edge of the site. Residual Bronze Age worked flints and Roman pottery,
suggest that the medieval site may overlie an earlier sequence of mound deposits buried at
greater depth than 1m. This is the only site identified by the evaluation that is likely to act as
a constraint on the development of the new mudflat.
Two other sites recorded as sheepfolds on 19th century maps (Sites 2 and 3) included
evidence for post-medieval and modern activity only. Of these, Site 2 (Trench 56) produced
pottery from the late medieval/early post-medieval transition (c 1475-1550), which was
recovered from the fill of a former channel. Site 3 included a brick sheep dip, which appears
to have been in use in the late 18th century but was made from what may have been
recycled 16th/17th century bricks. Site 4, another 19th century sheepfold, produced only
modern artefacts." (1)

<1> Oxford Archaeology, 2013, London Gateway, Site X, Cooling Marshes: Archaeological Investigation Report (Unpublished document). SKE31129.