The monument includes two v-shaped timber weirs, one constructed inside the other, located near the northern shore of the Blackwater Estuary to the south of the town of West Mersea, some 300m beyond the main sea wall. The complex was first recorded from the air in 1993, during a period of very low tides. The outer weir has walls with a width of 85m (north west-south east) and 110m (north east-south west). The inner weir has walls with a width of 100m (north west-south east) and 110m (north east-south west). The other weir has two further short lines of timbers on the outside of and running parallel to its south western side; the inner weir has three short lines of timbers running parallel to its main wall. These additional timber alignments probably represent successive modifications to the design. The two weirs have very elongated traps areas at their easternmost points; these would have housed the nets, and fish remains and processing deposits are expected to survive in and around them. The site is situated just below mean Low Water and is now largely sub-tidal. <1>