123rd Street Overlook
This decaying structure overlooking the Hudson River just to the west of Grant's Tomb is one of the numerous river overlooks in Riverside Park. This one includes an abandoned comfort station and is unique in having a roof, supported by marble columns and, perhaps, originally intended to shield small social occasions. This is a fairly remote section of the park, away from recreational areas and overlooking overgrown cliffs that descend to the highway and down to the river, thus negating any real need for a comfort station or such an ornate structure. But it seems that there is also no incentive to demolish it, leaving it as an anomalous ruin.