NEWBURY, ENGLAND—The PBS hit "Downton Abbey" has an unlikely but dramatic connection to the greatest Egyptological discovery of all time. The soapy Edwardian drama is filmed at Highclere Castle, seat of the Fifth Earl of Carnarvon, who sponsored the excavations that unearthed the tomb of King Tutankhamun. To mark the 90th anniversary of the discovery, a replica of the tomb has opened in the cellars of the nineteenth-century mansion, along with recreations of the pharaoh's coffin and death mask that complement original artifacts from the site that are also on display. "This is the defining thing for Highclere. Downton is lovely, but it will come and go," said Lady Fiona Carnarvon, the current Countess of Carnarvon. "In 100 years' time, people are still going to be wondering and admiring the discovery of Tutankhamun's tomb." Fans of the boy king will soon have added incentive to visit Highclere Castle. Next year the original tomb in the Valley of the Kings is slated to be closed to tourists for good.