New Structure Abandoned Lave Mines / Abandoned Gold Mines

It is in Minecraft's lore that Piglins mined out all Netherite and that's why there is ancient debris, so why not an abandoned mined in the nether. This could be a mine that goes under the lava making it dangerous and hard to traverse with lava pouring in the mine, it could also be filled with new fire based mobs so that it's very dangerous. But in order to make all this danger worth something the structure could spawn near very small veins of ancient debris and gold in netherack, this could be used to introduce new player's to the material as many Minecraft features have been trying to do so such as with ruined portals. A new mob that could be in this structure could be The Magma Crawler, a mole/worm like creature that swims between the bottom of lava lakes making use of the new structures layout of flooded lava areas and Basalt hallways to it's advantage. This mob could drop gold nuggets and bones, as it scavenges the remains of creatures that happen to fall in lava lakes.