A lecture about the Leningrad metro that could have looked completely different. Glass instead of stone, marble figures, illuminated ceilings, "horizontal elevators" and stations that are not on the map. There will be myths and revelations, details about the letter "M" and the color of the lines, plus many images from projects, diagrams, and posters. And also - rare finds on decor. Sometimes a city keeps a second version of itself - the one that never became a reality. The meeting will discuss the Leningrad metro, which was started to be designed and built, but some ideas remained on paper. Why did the first line become red, and how was the familiar letter "M" read differently over the years? Which "M" can be easily confused and where are the clues hidden? At the center of the conversation are early station projects and visual solutions that today seem fantastic: glass columns and walls, glass floors, illuminated ceilings, figures of "comrades with banners" and "marble people." We will analyze what was realized from the planned ideas and what disappeared from the plans, and why the city chose some options and rejected others. A separate topic is the "horizontal elevator." What is this principle, who invented it, and where could it have appeared? How do different versions differ and what would a "metro lift" look like in vertical execution? These questions reveal the logic of engineering solutions and how designers sought a balance between beauty, speed, and convenience. There will be stories about names that changed course, and about stations that could have appeared in different places. Where could "Liteiny Prospect" have been seen? Where did "Nakhimson Square" and "January 9 Garden" go? Are there "horses" in the metro and why do people sometimes argue about whose monument stands on the right platform? The format is live: questions with answers, riddles, debunking popular myths, and small tasks for those who love to look more closely. There will be many pictures, so the meeting will suit lovers of St. Petersburg, fans of urban history, and those who ride the metro every day and want to see more than just signs and diagrams. After the lecture, it will be easier to read the details - from m.