End spike

End spikes, also known as obsidian spikes, obsidian pillars, obsidian towers, and end pillars are a feature in The End biome that are made of obsidian.

Generation
End spikes generate naturally the first time the player enters the End, and regenerate when the ender dragon is respawned.

When the ender dragon respawns, any blocks the player had placed within 10 blocks in all directions of the bedrock block at the top of the end spikes  are deleted, as well as blocks inside the square containing the edge of the pillar down to y=66.

Construction
End spikes are composed of obsidian, with a single bedrock block and an end crystal on top of each pillar. They have circular forms.

The following 10 pillars generate in a 43-block radius circle around the exit portal in a random order (total of 40499 obsidian):
 * A 3-block radius pillar ending at y=76 (total of 1596 blocks of obsidian);
 * A 3-block radius pillar with iron bars ending at y=79 (total of 1659 blocks of obsidian);
 * A 3-block radius pillar with iron bars ending at y=82 (total of 1722 blocks of obsidian);
 * A 4-block radius pillar ending at y=85 (total of 3145 blocks of obsidian);
 * A 4-block radius pillar ending at y=88 (total of 3256 blocks of obsidian);
 * A 4-block radius pillar ending at y=91 (total of 3367 blocks of obsidian);
 * A 5-block radius pillar ending at y=94 (total of 5358 blocks of obsidian);
 * A 5-block radius pillar ending at y=97 (total of 5529 blocks of obsidian);
 * A 5-block radius pillar ending at y=100 (total of 5700 blocks of obsidian);
 * A 6-block radius pillar ending at y=103 (total of 9167 blocks of obsidian).

The bottom of all pillars are at Y level 0, which means that pillars are generated through the island.

The second and third shortest pillars include a cage comprised of 73 iron bars surrounding the end crystal, to protect it from projectiles.

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