Bath at Longleat House. Reacquiring occupation of this enormous 16th-century mansion, in a state of poor repair, following requisition during World War II, the marquess was faced with death duties of £700,000. The marquess opened the house to the paying public and kept the proceeds himself to fund the mansion. In 1966, to keep attendance numbers high, the peer went a step further and introduced lions to the park, thus creating Britain's' first safari park. After the initial opening of Longleat, the Dukes of Marlborough, Devonshire and Bedford opened Blenheim Palace, Chatsworth House and what remained of Woburn Abbey. With the example and precedent of "trade" set by those at the top of the aristocratic pyramid, within a few years hundreds of Britain's country houses were open two or three days a week to a public eager to see the rooms which a few years earlier their ancestors had cleaned. Others, such as Knebworth House, became venues for pop and rock festivals. By 1992, 600 "stately homes" were visited annually by 50 million members of the paying public. Stately homes were now big business, but opening a few rooms and novelties in the park alone was not going to fund the houses beyond the final decades of the twentieth century. Even during the stately home boom years of the 1960s and 1970s historic houses were still having their contents sold, being demolished or, if permission to demolish was not forthcoming, being left to dereliction and ruin. By the early 1970s the demolition of great country houses began to slow. However, while the disappearance of the houses eased, the dispersal of the contents of many of these near redundant museums of social history did not, a fact highlighted in the early 1970s by the dispersal sale of Mentmore Towers. The high profile campaign of Marcus Binney, eminent architectural historian and president of Save Britain's Heritage, failed to save the mid-Victorian mansion; and the subsequent departure from Britain of many important works of art from Mentmore caused public opinion to slowly change. The house had, in fact, been offered to the nation by its owners in lieu of death duties, but the Labour Government of James Callaghan with a general election in sight did not wish to be seen saving the ancestral home of an hereditary nobleman, and thus rejected the offer. However, that same year the destruction finally came to a