In Norway, in the city of Trondheim, out in the fjord, on the Island MunkHolmen is a building:

Observe the hemispherical chamber there, used to store gunpowder back in the old days.
The acoustics is unlike any other room on the planet... you guys better believe it!!!
So me and a friend sort of was on a guided tour on this Island, and when the rest of the group
followed the guide along and out of the room, we stayed back.
And what we did, oh my, we sung Amazing grace, the song at the top of our lungs!!!
I walked the outer circle, and he stood in the middle singing up towards the roof.
The experience was out of this WORLD!!!
The resonance, and amplifying effect of this chamber, gives chamber music a new meaning!!
It actually brings tears to my eyes just writing this now...

Hehe... Well.
Awesome experience! Just awesome!

Imperial