The coastline of Wales extends from the English border at Chepstow westwards to Pembrokeshire then north to Anglesey and back eastwards to the English border once again near Flint. Its character is determined by multiple factors, including the local geology and geological processes active during and subsequent to the last ice age, its relative exposure to or shelter from waves, tidal variation and the history of human settlement and development which varies considerably from one place to another. The majority of the coast east of Cardiff in the south, and of Llandudno in the north, is flat whilst that to the west is more typically backed by cliffs. The cliffs are a mix of sandstones, shales and limestones, the erosion of which provides material for beach deposits. Of the twenty-two princip