It's cute. If anything, I'm going to thank him for it.
Ooh, bunkers!
Ooooh, bunker complexes!
We only have small bunkers strewn about here in my area (that is, within 2 km of my house), which isn't to say that they aren't fun to explore (even though each bunker is finished in 10 seconds, and most of the time is spent walking to the next one). During our Germany trip this summer, however, we visited a bunker graveyard in Denmark. They were probably 30-40 bunkers randomly strewn about on the beach and in the water as the sea had claimed the land below them. Surreal yet awesome.
Also, I can attest to that it's really easy to find a completely dark spot in a sufficiently large bunker. I had some fun going into a bunker, hiding in a dark corner, jumping out to scare littlest brother and then run away from him to repeat the proceedure, and I managed to find a spot that was so dark that you couldn't see me even with your eyes fully adjusted to the darkness. The room was no more than 120-140 cm wide and the end was no longer than 2 m away from the door through which you entered it, and yet I managed to scare littlest brother as he did so and then completely evade him when came to exact revenge, jumping past him without him even managing to touch me, because I could see him, and he just couldn't see me.