Photo by Guy Harrop . The last castle to have been built in England, is to be saved from certain ruin thanks to a £2.5 million grant from the Heritage Lottery Fund. National Trust staff and volunteers celebrate the news of a £2.5 million grant from the Heritage Lottery Fund at Castle Drogo, Devon. Castle Drogo is the last castle to have been built in Britain, between 1911 and 1931 and was designed by the renowned architect Edwin Lutyens . Since its completion it has suffered major structural problems resulting in leaks and water penetration throughout the building . The announcement of the grant from the Heritage Lottery Fund will now ensure its conservation including restoration work of the large flat roof.