The ecological and/or landscape qualities of areas designated as Critical Natural Assets are so important, unusual or sensitive that:

•   they are at least of City-wide significance;

•   they could not satisfactorily be replaced or re-created elsewhere; and

•   their loss would seriously diminish Lincoln's ecological diversity or essential landscape character.

Areas designated as Critical Natural Assets include Sites of Special Scientific Interest (SSSIs); and Regionally Important Geological/ Geomorphological Sites (RIGS).