wooden walkway crossing marshland leading to observation point at estuário do douro local nature reserve in vila nova de gaia,

conservation biodiversity observation destination environment exploration perspective tranquility background horizontal wanderlust marshland cityscape boardwalk buildings landscape ecosystem discovery adventure crossing portugal estuario outdoors distance serenity exterior walkway leading esturio reserve wetland tourism habitat horizon freedom natural wooden nature scenic travel summer beauty golden colors point douro local porto clear sunny peace space vila nova gaia long blue