An archaeological excavation was conducted at Wygate Park, Spalding, to inform the construction of a proposed residential development. A saltern of Late Iron Age to early Roman date was encountered, comprising a hearth with a row of postholes immediately to its north, two probable settling tanks and a rectilinear enclosure ditch. The hearth was archaeomagnetically dated and its last heating event calculated at 130-240 AD (with 95% confidence). The ditch was truncated at its northern end by a natural creek dated by optically stimulated luminescence (OSL) to 490-650 AD. Other contemporary features were identified, including a segmented ditch truncated by a later 2nd century AD curvilinear enclosure, and a number of waste pits containing large quantities of briquetage and charcoal. Sealing many of the features on the site was a spread of briquetage. The entire site sequence was sealed by an organic layer representing a period of freshwater marsh, which was itself sealed by a layer deposited during a period of saltwater marsh OSL dated to 620-980 AD. No further human activity was noted on the site until a series of post-Medieval east-west aligned dylings. {1}{2}