In the 20th century a series of posts were found together with an early to mid Iron Age sword when a dyke was being cleaned near Fiskerton, near where the Witham Shield had been found. Excavations in 1981 revealed the posts to be a wooden causeway which dendrochronologists dated to a period between 457 and 300 BC. It appeared to have been repaired and added to every eighteen years or so during that period, even though the construction and maintenance of a walkway on such a scale at that time would have been a major feat of engineering. Hundreds of artifacts were also found around the causeway, including eleven spears, six swords, woodworking and metalworking tools, as well as part of a human skull which had a crescent-shaped chop mark, probably inflicted by a sword; this injury is unlikely to have killed the man.