The coastlines for versions 1.18 and above don't match up perfectly. Always select the version that was used to generate the chunks you're looking at. If you started your world on an older version, you'll have to switch between the versions in the app.

(for slime chunks) you didn't wait long enough, since they have a very low spawn rate even in slime chunks.

you used mods or resource packs that affect world generation.

you selected the wrong edition or version (the one used to generate the region you look at).

you entered the wrong seed or coordinates.

If your in-game world doesn't match the map here at all, it's most likely due to one of the following: Huge Abandoned City Map for Minecraft 1.8.If none of the below helps, please report in the comments and include your seed, platform and version, and coordinates. The thing is hollow, except for a few specific locations which the creator spent the time to thoroughly build. It’s just that it looks like it has a lot more substance than it actually does. Adding zombies and other baddies patrolling the streets could create a scenario like something out of a Resident Evil game, and there must be some players who would enjoy that. Really, the Huge Abandoned City map is best when used with some mods to make the empty city a little more interesting. To some, that room for improvement is a real selling point for this map. To fill every building on this map with insides would take months, or maybe even years of a person’s life. As you might imagine, many of the buildings are rather impressive from the outside but actually lack any kind of interior. That’s just one of the reasons you might want to check out the Huge Abandoned City map by JelleMC.

Places which were usually so full of people going so strangely silent can make them kind of creepy. There’s something eerie about large cities which have been emptied out and abandoned.

Best minecraft 1.12 city maps