3. South Street Diner: Finish the night at this famous, all-hours greasy spoon. Reflect on the evening with a "Dessert of the '50s": frappes, shakes, and floats, oh my! 178 Kneeland St., Boston, 617-350-0028. southstreetdiner.com
Prep work: See a map of the Retro Date suggestions.
(Erik Jacobs for the Boston Globe)