Pembrokeshire the County Council. The National Monuments Record of Wales of the Royal Commission on the Ancient and Historical Monuments of Wales identifies nearly 6,000 sites in Pembrokeshire as worthy of study, preservation and recording, including prehistoric and modern buildings, wrecks and natural features. There are 10 National Trust properties in Pembrokeshire. Music festivals in Pembrokeshire include those at St David's, Fishguard (folk, jazz and the International Music Festival) and Tenby (Blues Festival). Milford Haven's Torch Theatre produces drama, screens films and holds exhibitions of art and crafts, and there is a theatre-cinema in Fishguard (Theatr Gwaun) and a cinema in
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