Castlemartin, Pembrokeshire Castlemartin, Pembrokeshire Castlemartin () is a village in (and giving its name to) the Castlemartin Hundred, Pembrokeshire, Wales. It is part of the community of Stackpole and Castlemartin, after amalgamating with Stackpole in 2012, within the Pembrokeshire Coast National Park. The village is on a sandstone ridge, southwest of Pembroke, southeast of Angle, and reached on the B4319 road. In chronostratigraphy, the British sub-stage of the Carboniferous period, the 'Arundian' derives its name from Hobbyhorse Bay in the Castlemartin community"arundo" being the Latin for hobby horse. The village, once centred on a prominent Norman motte-and-bailey castle, together with the original
Pembrokeshire to its proximity to the relatively warm Atlantic Ocean. Inland, average temperatures tend to fall 0.5 °C for each 100 metres increase in height. The air pollution rating of Pembrokeshire is "Good", the lowest rating. The rocks in the county were formed between 600 and 290 million years ago. More recent rock formations were eroded when sea levels rose 80 million years ago, at the end of the Cretaceous Period. Around 60 million years ago, the Pembrokeshire landmass emerged through a combination of uplift and falling sea levels; the youngest rocks, from the Carboniferous Period, contain the Pembrokeshire Coalfield. The