Rarest structure you have seen

I have found a snowy abandoned village which is supposed to be rare

Wooden Mansion

Same

i found a stronghold that had good loot

A Nether Portal Remnant with an enchanted golden apple.

woodland mansion

camman18 said that

i found a ocean monument near spawn

Blacksmith that had 3 Iron Chestplate

In creative mode, I've found a woodland mansion with a base stretching down hundreds of blocks because it was on a mountain. There was a lush cave inside the base of the mansion. Also, in creative mode I've found a bastion remnant underground.
The rarest thing I've found in survival mode is...
I'm not sure, It could either be a nether fortress, a bastion remnant, or maybe a huge ocean monument (Or whatever the one with guardians is called).

wow that was a long note

Enchanted apples are O.P.

how many blocks from spawn

this is normal

I once found an ocean monument near spawn too

i spawned on an island on that seed

Gotta hate those island seeds

I found a dungeon literally poking out of a cavern in an abandoned mineshaft

loot was trash tho, just coal and bones

lol

I've found an abondoned mineshaft with 2 dungeons in in and connected to a deep dark (It was super creepy because of all the sculk but it was a great xp farm)