cliff coast face fleshy fractured Great Britain green leaf leaves natural nature navelwort plant rock Umbilicus rupestris united kingdom wales welsh arch chalk England hole kent landscape low peephole sea shore sky stone tide coastline Cornish cornwall english field grazed meadow ocean stark water waves Balearic Islands creepy drop eerie footpath limestone majorca overhang path pilgrims Spain steep trail trees unnerving bay crumble crumbling danger dangerous hazard hazardous high sheer south summer white Birling Gap cream evening height rockfall Sussex broken Catalan catalonia Catalunya costa brava cracked damaged endurance endure fissured flowers spanish success tenacity umbellifer worn flower flowering plant groundcover herb petal purple Terrestrial plant thyme Thymus serpyllum wild beach erode erosion sand stacks