I came up with this idea late, so don't be surprised that i didn't enter it into the minedeas contest. Anyways, this implementation would add rough circles of stone monoliths (columns) to the game, somewhat like Stonehenge.

These stone circles would appear in the plains or desert biome, and would consist of four 2x3 columns and four 2x2 columns, all 6 blocks tall, alternating to form a circular shape as shown, made of mossy cobblestone. The total height would actually be 7, if you count the mossy cobblestone walls on top of each monolith. Inside the stone circle is a platform with four mossy cobblestone wall archways, aligned with the 2x3 monoliths. in the middle of the platform would be an incomplete altar similar to the Herobrine altar, but with varying base materials. (usually emerald or iron, but Herobrine Gold on rare occasions.) To activate an altar, you must first complete it as shown in the video above, and ignite the netherrack block. A geyser event lasting 30 seconds will then commence, raining emeralds or iron ingots (depending on the base material).

If you activate a Gold altar, Herobrine will appear in the flames. He shoots fireballs at you, and he has 8 hearts of health, as well as resistance to fire, projectiles, and potions. If you kill Herobrine before he vanishes, you recieve a Blazing Soul, which can reactivate altars or spawn a new one in a flat area of the correct size. This can also be done in the Nether or the End, producing a unique Stone Circle for each dimension.

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