Apologies as this is not really a Hauptwerk related topic but I am fascinated looking inside organs. There is something about seeing rows and rows of shiny pipe ranks, glittering, neatly ordered on their soundboards. It raises the hair on the back of my neck. Even the big woodies fill me with awe.
I have always inspected the insides of organ where I have been organist, sometimes getting a cloth out to give them a good polish...only kidding, I leave that to the organ builders
The largest organ I have inspected was at the Royal Albert Hall, London. I was playing it for a weekend of concerts and services in 1994. The organ curator took me on a tour inside and it was fascinating. He pointed out the huge double level swell box. Apparently the organ builders with the hall management held dinner parties in it to raise money for the organ before they installed the pipework.
What big organs have you been inside of?