Action Comics #386 " The Home for Old Super-Heroes "
Superman is trapped by the Time Master and becomes the loneliest superhero in the universe. Now he can only travel forward in time. Everyone he ever knew in 1970 is dead. He is immortal but he can age and he finds himself in a retirement home for heroes in the far future. Superman travels even further into the future, in which super-powers are outlawed due to a disaster involving three super-heroes of the past. He is sent to the world of Diodn to live with other aged super-heroes, but leads them in an operation to save the Metropolis of that era. The mayor of Metropolis vows to get the anti-super-hero law rescinded.