Flat Holm is the most southerly point of Glamorgan and Wales .
South easterly from Lavernock Point , roughly three miles out in the Channel Estuary is Flat Holm , an island which although geographically is within the Vale , is administered as part of the city of Cardiff .
island   is the most southerly point of Glamorgan and Wales .
South easterly from Lavernock Point , roughly three miles out in the Channel Estuary is Flat Holm , an island which although geographically is within the Vale , is administered as part of the city of Cardiff .