This mod adds 2 structures, with no new blocks, items or mods.

1. Ruined Aether Portal (Ocean)
2. Ruined Aether Portal (Regret) This mod does not require the Aether to work.

Ocean variants only spawn in deep ocean biomes, while Regret spawns in forests. I couldn't figure out how to add loot chests, so instead they just have a single, empty pot with the portal (which is made from glowstone and raw gold.) Regret also has a bit of prismarine blocks, to simulate the aether's grass.

This mod was made in about 2 days with Mcreator.