The fogou at Lower Boscaswell had been mentioned by earlier writers, but it was not fully excavated until 1954 and 1955. These excavations revealed the main gallery, side passage, and an associated courtyard enclosure, making the site especially valuable for understanding how fogous were built and used within later prehistoric settlements. The site was first recorded in the nineteenth century. Buller mentioned it in 1842, linking the area with traditions of an “old castle” and reports of Roman coins. Blight described the fogou in more detail in 1864, recording its visible structure and comparing it with other Cornish and Celtic underground sites. Neither Buller nor Blight excavated the monument, but their accounts preserved important evidence for features that were later damaged, hidden, or altered. The 1954 excavations showed that the fogou was built from large granite slabs and squared stones. It included a curved passage running east to west, with only two original roof lintels still in place. Modern walling had blocked parts of the structure, while a substantial wall near the entrance suggested a former northern approach. These features indicate that the fogou was part of a larger settlement complex rather than an isolated underground chamber. One of the most significant discoveries was the eastern enclosure, which appears to have been directly connected to the fogou. This may represent a courtyard house or courtyard structure built on earlier foundations. Excavation revealed carefully constructed stone walls, a stone step feature, and changes in walling that marked the transition from the underground passage into the above ground enclosure. If correctly interpreted, this makes Lower Boscaswell one of the clearest examples of a fogou physically linked with a courtyard building. Finds from the excavation, including pottery identified by Charles Thomas, place the site in the La Tène period of the Iron Age. The side passage was also shown to end in a well built doorway, correcting earlier suggestions that it continued towards the village. Local traditions add another layer to the site’s history. Stories recorded from Boscaswell describe punishment for disturbing ancient wells and chapels, reflecting a continued respect for old sacred places. Together, the archaeology and folklore make Lower Boscaswell an important site for understanding Iron Age settlement, fogou architecture, and the later cultural memory of ancient places in Cornwall.