Scheduled Monuments in Pembrokeshire along with a wide variety of post-medieval sites from coalmines, kilns and dovecotes through to World War II defensive structures. Scheduled Ancient Monuments (SAMs) have statutory protection. The compilation of the list is undertaken by Cadw Welsh Historic Monuments, which is an executive agency of the National Assembly of Wales. The list of scheduled monuments below is supplied by Cadw with additional material from Royal Commission on the Ancient and Historical Monuments of Wales and Dyfed Archaeological Trust. Scheduled Monuments in Pembrokeshire Pembrokeshire is the fifth-largest county in Wales, but has more Ancient Monuments (526) than any except Powys. This
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