Encountered my first desert temple - almost died.
I fell far enough to be left with two Health, and landed next to a floor plate.
Beneath the floor plate was a square of nine blocks of TNT - I think that had I landed on the plate not only would I have died in a spectacular fashion, but the temple would have been destroyed.
The gods of irony also paid me a visit - I had started work on a ruined temple, just for the look of it. The temple was on the other side of the hill, less than a mile from where I started to build my folly. (I picture my little place as a tourist trap.... Come see the pristine wilderness of the jungle - with the underbrush cleared away. Visit native ruins! Built out of cinder block and plaster....)
I also found a mine, directly between my home and the temple - I discovered the temple after completely filling my inventory, made a full stack of ladders out of mine timbers, built a column of stone in the center of a huge chamber.... came out of my hole in the ground and went 'ooOOooh! What's that?' At first I thought that it was part of a village, then I got a better view.
by , on Flickr
I added some torches, but otherwise left it as I found it.
The Auld Grump
(I found that out by accident - paced a log instead of the block I was trying to place and went 'oh'.)
Chiseled Stone is in even shorter supply - I have only found one Jungle temple to steal it from. I have about twenty left.