In 1859 Francis D'Arcy-Osborne, the Duke of Leeds, died, leaving Conisbrough to his nephew, Sackville Lane-Fox, the Baron Conyers. The keep remained in good condition, but by 1884 it was apparent that repairs were needed and the antiquarian George Clark recommended urgent work to repair the stonework. If finances allowed it, he also urged the reinstallation of a roof and wooden floors. Limited repairs were subsequently approved by the trustees of Lord Conyers, although Clark's colleague, A. Ellis, expressed concerns that railings to protect the visitors who routinely climbed to the top of the keep had not been funded. A reported £500 was spent by the trustees renovating the castle ruins, including the construction of a lodge in the outer bailey for the castle keeper, completed in 1885, and improvements to the footpaths.