A possible concise summary is:
The speaker narrates three stories of places that are dangerous or forbidden to visit, such as a nuclear fusion reactor in South Korea, a mysterious cave near Area 51, and an underwater cave in Florida. He also shares his personal experience of diving under a barge and feeling claustrophobic. He invites the audience to comment on which place they would like to explore and why, and promotes his social media channels.
Here are some possible key facts extracted from the text:
1. The text is a transcript of a YouTube video about three places that people should not visit.
2. The first place is the Paris catacombs, where a man was filmed running away from something and never seen again.
3. The second place is the M cave near Area 51, where a hiker claimed to feel a strange vibration and later disappeared while looking for it again.
4. The third place is the Vortex spring cave, where a diver went past a locked gate and into a dangerous underwater cave and never came out.
5. The video was made by John Ballen, a former Navy SEAL who shares stories of the strange, dark and mysterious on his channel.