Langness Coastal Battery (Napoleonic/Victorian)

The Langness peninsula had coastal defence positions from the Napoleonic period onwards, upgraded during Victorian times and both World Wars. The peninsula guards the approaches to Castletown and Derbyhaven. Multiple military periods layered on the same strategic ground. Also one of IoM's richest shipwreck zones (HMS Racehorse, plus many others). WHY: Military positions = dropped military items across 200+ years. Langness is also a detecting-friendly landscape — short grass, rocky foreshore, relatively flat. The combination of military + shipwreck + medieval (near Castletown) makes Langness one of the most productive detecting areas per square metre on IoM. Especially check around the lighthouse, the old coastguard station, and any visible earthworks.