A possible concise summary is:
A group of urban explorers from Ukraine visit a secret bunker in Budapest, Hungary, that was built for the communist party in the 1950s. They sneak into the bunker through a well-house and find various rooms, equipment, and documents related to the bunker's history and purpose. They also discover that the bunker is connected to the metro system and decide to wait until the night shift is over to explore the metro tunnels. They encounter some challenges and dangers along the way, such as sensors, cameras, workers, and water. They film their adventure and share their commentary with their viewers.
Here are some possible facts extracted from the text:
1. The text is a transcript of a video where a group of explorers visit a secret bunker in Budapest, Hungary.
2. The bunker was built in 1953 for the members of the Hungarian communist party and the parliament, in case of a nuclear attack or air raid.
3. The bunker is connected to the working metro system and has a hermetic door that can block the tunnel from explosion, water or radiation.
4. The bunker has a ventilation system, a diesel generator, an elevator and a water reservoir, but most of them are not working or flooded.
5. The explorers have to avoid being caught by the metro workers or the security cameras, and they have to wait until the night shift is over to enter the metro tunnel.
6. The explorers are from Kyiv, Ukraine and they compare the bunker to the Soviet vaults they have seen before.
7. The explorers wear hoodies with their logo and they make jokes and comments about their adventure.