bird coast coastline lake Nyberg pair spring sun sunset swan swans swimming two water duck ducks flying grass lyme ocean sea straw estuary low Mud mudbank natural nature pattern rill texture tidal tide bands beach cave chalk cliff danger flint Italy shore summer white blue cloud islands islets mountain mountains Natural landscape norway rainbow rocks sky water resources architecture Arnside cumbria England english Great Britain Jetty leisure Morecambe Bay pier sandflats view fjord frozen HDR ice icy rock sand season stone tree winter buildings channel hazard houses lighthouse norwegian passage promontory town warning footprint footprints holiday path walk bridge footbridge Sussex wooden