Someone just scanned wikipedia
All of what I listed have HUGE inconsistencies with what was told to the public and still is under a lot of secrecy.
The Duga for example was said to be an over-the-horizon radar system (which didn’t work that well). Despite this: they kept it online for years, still patrol it to this day and only abandoned it due to radiation from Chernobyl. Also, nations looking into it saw it as a potential weapon and not a radar system and it was so powerful you could pick it up on shortwave pretty much world wide.
The Avrocar’s design documents posited it might achieve 50,000 feet and go 3,000+ miles per hour, yet only two are known to exist and the technology was left abandoned due to a lack of funding. All of that is ignoring the saucer shape of the craft.
Project Popeye is still under a lot of secrecy, to the point no one is even sure how successful it was. It far exceeded what they estimated from cloud seeding and no one knows what advancements they made have made after the fact.