The park at the bottom of the Porter Valley beside Ecclesall Road, opened in 1887 to mark Queen Victoria's golden jubilee. A memorial marks the crash of the Mi Amigo, an American B-17 bomber, on 22 February 1944, when all ten crew died avoiding children playing in the park; Tony Foulds, one of those children, tended it for decades. The park is the start of the walk up the Porter Brook to Forge Dam.
Wikipedia: Endcliffe Park