Thanks to Flickr user stopani6 for telling me this is Russia, and mixtara for saying that this is in Dubna, north of Moscow.
I had this labeled London originally and had this comment: "This could be Moscow, but the slide numbering makes me think it's London. Perhaps a viewer recognizes the clothing styles in capitalist and communist countries in the 60s?"
Taken by my grandfather David C. Cook on the way to a visit to Moscow for a meeting of the International Electrotechnical Commission. Scanned from an unlabeled Kodachrome slide number 2 3 in a slide cartridge marked "Russia".