Moscow tram (streetcar) on the 28 line from M. Sokol to Pr-t Marshala Zhukova. These ran in two-car trainsets from the suburbs, manufactured by KM. Thanks to Flickr commenters for pinpointing the location.
Photo by my grandfather David C. Cook. Scanned from an unlabeled Kodachrome slide, date stamped June 1969 frame 21. In a slide cartridge labeled "Russia".