Large rocket in Gaping Gill Main Chamber on a BPC winch meet.
Airbell full of tinkling light bulbs in a sump downstream of the old 5 Arches section of Peak Cavern show cave.
Underwater passage pre-decorated with tinsel on the day it was explored in Clapham Beck Head (after a flood in Ingleborough Cave had flushed away the Christmas grotto).
Walls ice cream box (aluminium) washed into one of the Far Canal outlets in Speedwell (recovered, bashed back into shape - and still used as a weekend grub box).
Ammo box in airbell in Giants Hole (in one of the streamway sumps) containing roll of elastoplast priced 1 shilling and 6 pence together with an immaculate carbide lamp with 1960s style wire hook (as opposed to 1970s-onwards helmet clip) - now on mantlepiece.