We've seen a lot of different shelters, and it seems hard to surprise us. But this one definitely stands out. And it becomes clear already at the entrace.
This is how the entrance / exit look like. We can enter through a thick iron door of the arched shape to see the space of a weird configuration. Inside is a dead-end aisle that blasts blow-off.
The building consists of three "tubes". The central tube has toilets inside, bathroom and three small switching rooms. The side tubes are used for storage, also have two filtration and ventilation machines and some other rooms.
Some room with old diagrams
Room to the right from the central tube.