Wentworth Castle College of Education, until 1978. It was then used by Northern College. It was featured in the Victoria and Albert Museum's exhibition "The Country House in Danger". The great landscape that Walpole praised in 1780 was described in 1986 as now "disturbed and ruinous" with several listed structures put on English Heritage's at-risk registry. The second earl's sinuous river excavated in the 1730s was reduced to a series of silty ponds. Wentworth Castle Gardens, the only Grade I-listed parkland in South Yorkshire, underwent £20m worth of investment from 2002 to 2017. The Wentworth Castle Heritage Trust was formed in 2002 as a charity with the aim "to undertake a phased programme of restoration and development works which will provide benefit to the general public by providing extensive access to the parkland and gardens and the built heritage, conserving these important heritage assets for future generations." The restoration of the Rotunda was completed in 2010 and the parkland has been returned to deer park. The estate opened fully to visitors in 2007, following the completion of the first phase of restoration, which cost £15.2 million, Further restoration was completed in 2014. Wentworth Castle was featured on the BBC TV show Restoration in 2003, when a bid was made to restore the Grade II* Listed Victorian conservatory to its former glory, though it did not win in the viewers' response. Subsequently, the Wentworth Castle Heritage Trust took the decision in 2005 to support the fragile structure further with a scaffold in order to prevent its total collapse. The Trust succeeded in raising the £3.7 million needed to restore the conservatory in 2011 and work began in 2012, with grants from English Heritage, the Country Houses Foundation, the Heritage Lottery Fund and the European Regional Development Fund. The Trust completed the restoration of its fragile Victorian glasshouse in October 2013 – 10 years after its first TV appearance the Restoration series. It was opened by the Mayor of Barnsley on 7 November 2013 and opened to the general public the following day. Despite attracting 10s of thousands of visitors a year, Wentworth Castle Gardens was forced to close in the spring of 2017. During the closure years a small team of gardeners and a group of community volunteers carried out essential maintenance of the gardens and curated an archive of material about the site's history. In September 2018 it was announced