Eastbourne is where Constance goes after it is announced that Lucy was to marry Frank. Phyllis also took a trip to Eastbourne to visit the Devonshires' Place. Eastbourne is a well-off, resort town in England. It has large, sea-side cliffs. It was founded on the basis of a railroad. The town's development was founded based off of the Duke of Devonshire. The fact that Eastbourne is the vacation spot for Constance and Fred further demonstrates the financial divide between the Devonshires and the Lorimers.
“At Eastbourne she had amused herself with getting up a tremendous flirtation with Fred, to the Devonshires' annoyance and the satisfaction of the victim himself, whose present mood it suited and who hoped that Lucy would hear of it.” (Chapter XVII)
Click to see an image of historic Easbourne