Conflict archaeology is a popular subject of academic research. Within the topic of British Second World War archaeology there are few studies examining anti-invasion defences, and none relating to the evidence or its use. This research was influenced by concepts in historical and conflict archaeology and the archaeologies of the recent and contemporary past. It was undertaken to determine the extent of survival of archaeological, documentary, aerial photographic and cartographic evidence for three cases in south and south-west Wales. Case study method was used to identify, select and analyse evidence. Grounded theory was used to induce meaning. The evidence was given equal primacy, assessed critically and analysed for its role, value and contribution. Official sources were used for their unique, informed and authoritative content. Knowledge of military organisational practices and formation/unit identities were required to use the evidence effectively. A rich but incomplete evidence base of a complex character was identified. Evidence was found to be complementary and inter-dependent, representing aspects of a common shared phenomenon. The diverse sources could be used to induce meaningful narratives. The research suggested that an archaeological approach was a valid and effective form of inquiry when applied to cross-disciplinary evidence from the recent past.