For those who played in the older versions of Minecraft, this structure will sound familiar.

This is the Brick Pyramid, an old structure that appeared in Infdev versions of minecraft at the beginning of 2010. They were the first structures ever add in the game along with Starter Cobblestone Houses and Obsidian crosses.

They were completely solid, so they had no interior rooms. They were also really big, measuring 63x63x32 blocks each one.

They had a fixed position that does not change between seeds, so they were located in the exact same coordinates in all the worlds (only Y axis was modified between seeds). Even knowing that, these were extremely difficult to find having a rarity similar to the current Woodland Mansions.
For those reasons I decided to bring them back to the new versions of Minecraft as natural structures, as are the Villages or Desert Pyramids.

-They are now found in Deep ocean biomes and their variants.-They are generated in the ocean floor at a Y axis of 32.-They have a rarity similiar to the Nether Bastion Remnants, so these are not as rare to find as the originals.