Pembrokeshire is a county in the south west of Wales. The county is home to Pembrokeshire Coast National Park, the only coastal national park of its kind in the United Kingdom, which includes a 186-mile walking trail, the Pembrokeshire Coast Path. In the north of the county are the Preseli Hills, a wide stretch of high moorland with many prehistoric sites and the probable source of the bluestones that were used in the construction of the inner circle of Stonehenge in England.