How to find a village, stronghold or trial chamber without cheats
The in-game ways, and the one that only needs your seed: the closest structures with their coords, on Java and Bedrock.
Updated on .
/locate finds any structure, but you need cheats for it, and on Bedrock that turns off achievements for that world. There are two other ways: the clues the game gives you, and your seed.
Using the game's own clues
Strongholds: throw an eye of ender and follow it. Throw another one a few hundred blocks away and the two lines cross right on the stronghold. The stronghold finder does the math for you from the two throws, no seed needed.
Mansions and monuments: cartographer villagers sell explorer maps to the closest one. Since 26.3 (and the same update on Bedrock), the chests of abandoned camps can have maps to trial chambers, ancient cities and other camps. Ruined portals, shipwrecks and temples: you walk. Or you fly.
With your seed, in a minute
Get your seed (here's how), then open the structure finder: pick the structure, type your seed, version and where you are, and you'll get the closest ones with coords, distance and direction, the same thing /locate would tell you. The most popular structures have their own page too: the village finder, the trial chamber finder and the ancient city finder.
The seed map shows everything at once: spawn, every structure, the strongholds and the biomes, in the Overworld, the Nether and the End. It works on Java and Bedrock, which place structures differently, so pick the right edition.
Is that cheating?
Nothing changes in your world and you don't run any command: you're just reading a map of a world the game already generated. Achievements and advancements stay on. On a server it's up to the admin to share the seed, and the seed cracker guide covers the rest.
Questions
Does /locate really turn off achievements?
On Bedrock, yes: turning cheats on turns off achievements for that world, forever. On Java, to use commands you need cheats on when you create the world or through "Open to LAN", and advancements stay on anyway.
How deep are strongholds, ancient cities and trial chambers?
Strongholds are underground, usually right under where the eye of ender drops. Ancient cities are at Y -51 in the deep dark. Trial chambers are between Y -40 and Y -20. The finders give you X and Z, the rest is digging.
The structure is not where the finder says!
Double check the edition and the version first: the same seed places structures differently on Java and Bedrock, and some of them moved between versions. If both are right, it's one of the rare spots the game skips (Bedrock does it a bit more often).