Rare Photos of Kennedys in Cape Cod Up for Auction

 Dozens of never-before-released candid images of John and Jacqueline Kennedy swimming, relaxing, boating and simply enjoying the Cape Cod shore are going up for auction.

The lot includes an original photographic proof booklet, containing 27 images.

The unpublished images were taken by Washington Post heiress Katharine Graham at Bunny Mellon's Cape Cod beach shack in August 1961.

The 26-acre Mellon estate, in Osterville, Massachusetts, not far from the Kennedy's Hyannis Port compound, featured 1,000 feet of continuous shoreline, and was sold in 2013 for nearly $20 million.

Bobby Livingston, RR Auction's executive vice president, says the images are "exceptionally private, unrehearsed moments" that "convey a carefree happiness."

Bidding on the lot begins Feb. 12, and a live auction is scheduled for Cambridge on Feb. 19.