I have pictures and info on the Throne Room in the Forgotten Ruins. the only problem is I don't know how to make a new page on the wiki for it. So with much hope I will post it all here so someone else with the ability to do so will make the page.

It seems to spawn 350 blocks away from the core. It has 31 ancient crates, a larger one and a loot pillar. Its main building things are 78 stone brick walls, 2 stone pedestals, with 2 Caveling Skulls on them, a Caveling throne, 26 stone floor tiles, 16 Caveling floor tiles, and 8 dark Caveling floor tiles with the Throne room sigil directly in the middle. 2 of the Stone brick walls have ancient gemstones in them. The room on the inside is 16 x 16 minus the corners and the outside inculding the drop into nothing and the floor around it is 24 x 24 again minus the corners.

I'll post the images later because of the limit in the comments.