Cave Seeds

By the ChunkScan Team · Updated 2026-08-19

Deep Dark Seeds for Sculk Hunters

The deep dark is the only place to farm sculk blocks in bulk, and ancient cities are the only structures that hold Swift Sneak books, echo shards, and the disc fragments for Disc 5. The problem is finding one: ancient cities generate far below y=0 and give no surface hint, so on a random seed you can cave for hours before hitting sculk. The seeds on this page remove that search. Each one was scanned from real world generation, and every listed ancient city coordinate is an actual structure position, not a guess. The closest example here puts an ancient city 80 blocks from spawn; several others stack two cities or add trial chambers within a few hundred blocks, so one caving trip covers both 1.21 loot tables.

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What Makes a Good Deep Dark Seed

Three things matter. First, ancient city distance from spawn: the city marks a guaranteed large deep dark biome, so a close city means a close sculk farm. Second, multiple cities in range: loot chests per city are finite, and Swift Sneak III is not guaranteed in any single chest, so two cities within render-of-spawn distance doubles your odds per trip. Third, support structures: a nearby ruined portal supplies obsidian and sometimes gold gear for Piglin bartering, and trial chambers sit at similar depths, letting you chain underground objectives without surfacing. Every seed below is Java Edition and was selected on exactly these criteria.

How ChunkScan Verifies These Seeds

ChunkScan runs actual Minecraft world generation code against each seed rather than predicting placements from spawn algorithms alone. Our scanner has processed over 1.7 million seeds, recording spawn biome, the surrounding biome layout, and exact structure coordinates with straight-line distances from the world spawn point. Out of those 1.7 million seeds, only 20 pass this topic's filters, which is why hand-searching for a spawn-adjacent ancient city rarely works. The coordinates listed with each seed are the positions the game itself generates, so you can type them into an F3 debug screen or a command and dig straight down knowing the city is there.

Seed -9222864041198461032: An Ancient City 80 Blocks Out

This is the shortest walk to sculk in the dataset. You spawn in a meadow with an ancient city at 48, 64, just 80 blocks from spawn, close enough that a staircase mine from your first base lands in the city. Trial chambers generate at 64, 128 (143 blocks out) and a ruined portal sits at 128, 96, so all three early objectives fit inside a 160-block radius. When the first city is stripped, a second ancient city waits at -160, 224, only 275 blocks from spawn. Two cities and a trial chamber within 300 blocks makes this the best all-around pick on the page.

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Seed -9222824765921714211: Spawn on Top of Trial Chambers

This seed records trial chambers at 0, 0, distance zero, meaning the structure generates directly beneath the spawn point in a flower forest. Dig down and you are inside 1.21's mob-gauntlet structure before crafting an iron pickaxe. The ancient city at -256, 48 is 260 blocks away, so the natural progression is trial chambers first for gear and trial keys, then a short overland trip west to the deep dark. Two more ruined portals at -368, 16 and 96, -368 cover early Nether access, and a second trial chamber at -336, -208 gives you a fresh set of vaults.

Seed -9223214314906176716: Two Cities, Two Chambers

Spawning in an old growth birch forest, this seed pairs an ancient city at 160, 144 (215 blocks) with a second at 240, -272 (362 blocks). Both cities sit east of spawn roughly 400 blocks apart from each other, so a single tunnel at deep-dark depth can connect them into one looting circuit. Trial chambers at 0, -240 and -304, 64 flank the spawn on the other axes. If your goal is maximum Swift Sneak and echo shard chances per hour, two cities this close is rare: seed -9222986545718698563 also has two cities, but at 439 and 497 blocks, both noticeably farther.

Reading the Coordinates Before You Dig

Structure coordinates in the listings are horizontal x and z positions; distance is measured from world spawn. Ancient cities center around y=-51, so navigate to the listed x/z on the surface, then stair-step down rather than digging straight into an unlit void. The city bounding box is large, roughly a couple hundred blocks across, so hitting the listed coordinate puts you inside or beside it even if your tunnel drifts. For trial chambers, which generate between the surface and deepslate layers, listen for trial spawner ambience as you descend past y=0. Bring wool blocks: walking on wool does not trigger sculk sensors.

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Sculk Hunting Without Waking the Warden

Sculk shriekers summon a warden after four activations, so the loop is: crouch everywhere, place wool along your path, and silence or mine shriekers with a hoe before looting. Swift Sneak books, found only in ancient city chests, remove the crouch-speed penalty and are the single biggest quality-of-life upgrade for repeat visits, which is why the two-city seeds above matter. Collect sculk sensors and shriekers with Silk Touch for redstone builds, and sculk blocks for XP storage: each sculk block drops one XP when mined without Silk Touch. If a warden does emerge, run; it has 500 health and is not meant to be fought early.

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Frequently Asked Questions

Which seed has the closest ancient city to spawn?
Seed -9222864041198461032 generates an ancient city at 48, 64, only 80 blocks from spawn, with a second city 275 blocks out and trial chambers 143 blocks away.
How rare are seeds like these?
Very. Out of more than 1.7 million seeds scanned by ChunkScan, only 20 match this page's filters for spawn-adjacent deep dark structures, all verified with real world generation.
Do these seeds work on Bedrock Edition?
No. Every seed listed here was scanned on Java Edition 1.21. Bedrock uses different structure placement, so the same seed number will not reproduce these coordinates.